As new users of the GGreg20_V3 module may have noticed, the board now comes in black. The black PCB is likely the tenth generation of the GGreg20_V3 module. This version features an improved circuit for smoother high-voltage regulation and a voltage limit of approximately 600 volts.

The module also comes with two stickers. The first is a Q.C. (Quality Control) sticker on the back of the board. The second is a VOID (warranty) sticker placed on the module’s high-voltage adjustment potentiometer.

Since implementing these changes—over six months ago—we’ve had the opportunity to gather feedback from our customers. One of the most common questions directed at our support team has been about the VOID sticker. Naturally, people are curious (and sometimes even genuinely frustrated) about why we’ve restricted high-voltage adjustments and what this sticker actually means in practice.

Let’s go over everything step by step.

Over the past year (2023–2024), we grew increasingly concerned about the statistics on sudden module failures. Diagnostics consistently pointed to excessively high voltage as the likely cause. Over time, this inevitably damages module components and can even lead to the failure of the Geiger tube.

That’s why, starting around September–October 2024, we introduced several improvements to our internal quality control procedures. The Q.C. sticker is now applied at the final stage of product testing.

Additionally, we decided to further restrict access to the potentiometer’s settings.

Since the module requires precise tuning and this part of the circuit is analog, the potentiometer’s setting can be easily disrupted—whether during use, due to vibrations in transport, or for other reasons. We hope that the VOID sticker now serves as an additional safeguard, keeping the potentiometer fixed in the position set by our specialists.

This sticker also acts as a warning for both beginners and experienced users: if you’re not sure, don’t touch it.
Our goal is to ensure that anyone considering adjusting the potentiometer first makes sure they know what they’re doing, understands the correct procedure, and has the necessary tools.

Now, what about cases where adjusting the high voltage is actually necessary? As far as we know, there is only one such scenario: when replacing the Geiger tube with one that requires significantly different operating voltage.
For example, if you’re swapping a J305 tube for an SBM20 (or vice versa), there’s no need to adjust the module, since their recommended operating voltages are almost the same—380V for J305 and 400V for SBM20. However, if you’re replacing a J305 with an LND712, then an adjustment is necessary to change the operating voltage from 400V to 500V.

Some customers have asked: What should I do if I absolutely need to adjust the potentiometer to a different voltage?

Warning!

The module operates at voltages that can be hazardous to health and life. Do not violate safety regulations or electrical installation standards. If you’re unsure, it’s best to consult a qualified specialist with the proper experience and certifications.

Our Recommendations

1. Review the technical note on initial self-diagnosis of voltages on the GGreg20_V3 module.
2. Use the knowledge gained (see point 1) to correctly measure the voltages on the module without adjusting the potentiometer. Ensure that you are using the appropriate measuring tools and following the procedures outlined in the note.
3. Contact (via email) our support team to inform us that you plan to adjust the settings. If needed, consult with our specialists for guidance.
4. Adjust the potentiometer to the required voltage by removing the VOID sticker.

Conclusions:

• Since implementing Q.C. and VOID stickers as part of our improved procedures, we have not received a single report of GGreg20_V3 module failure.
• If you need to replace an SBM20 tube with a J305, there is no need to adjust the potentiometer. The operating voltage ranges of these Geiger tubes overlap, so you can simply swap the tube.
• Every module shipped with a Q.C. sticker has been properly calibrated and extensively tested. Our test bench records measurement statistics to verify the performance and stability of both the module and the tube over an extended testing period—typically about an hour. Only after passing these tests does our specialist approve the module for shipment.
• The extended final testing phase also allows for selective thermal control of module components, ensuring long-term reliability.
• The VOID warranty sticker on the potentiometer does not restrict you as a user. It simply serves as a warning that adjusting the potentiometer without proper knowledge and tools is dangerous. By breaking the VOID seal, the user knowingly accepts the associated risks.
• If you follow the documentation and handle the module correctly, you won’t need warranty service, repairs, or replacement for your GGreg20_V3.
• Simply leave the VOID sticker intact and avoid adjusting the settings unless absolutely necessary.

Testing methodology

To conduct the measurements, we developed a special test bench based on the Home Assistant platform. The central element of the system was the Raspberry Pi Pico W controller with ESPHome firmware, which controlled the operation of the GGreg20_V3 module. To accurately measure the energy consumption, we used an INA219 sensor connected to a NodeMCU/ESP8266 controller also running ESPHome firmware. We used a laboratory power supply as a power source for the GGreg20_V3, which set the exact voltage level during testing.

Since the GGreg20_V3 module supports a wide range of supply voltages, from at least 3.0V to 5.5V, we used the three most common supply voltage levels to show how the test result differs: 3.3V, 3.7V, 5.0V. These voltages give us an idea of the module’s consumption when powered by:

• another controller or source with a voltage of 3.3V;
• a 3.7V lithium battery;
• another controller or source with a voltage of 5V.

It is important to note that the INA219 sensor measured only the power consumption of the GGreg20_V3 module, while the controllers were powered separately. This allowed us to obtain the most accurate data.

Also note that the supply voltage level did not change over time during the 60-minute test. Therefore, you should not expect that we have performed a complete emulation, for example, of a lithium battery that discharges under load and, accordingly, loses voltage from 4.2V to 2.5V during the test. Although this would have been a really useful and interesting experiment, we decided not to bother with it that much.

Test bench

Software on the side of the measuring sensor of consumed electric energy based on ESP8266 + INA219 with ESPHome firmware:

sensor:
 - platform: ina219
 address: 0x40
 shunt_resistance: 0.1 ohm

 current:
 name: "INA219 Current"
 accuracy_decimals: 5
 id: current_value

 power:
 name: "INA219 Power"
 accuracy_decimals: 5
 id: power_value

 bus_voltage:
 name: "INA219 Bus Voltage"
 accuracy_decimals: 5

 shunt_voltage:
 name: "INA219 Shunt Voltage"
 accuracy_decimals: 5

 max_voltage: 32.0V
 max_current: 3.2A
 update_interval: 1min

 - platform: integration
 name: "Total Energy Consumed"
 id: total_energy
 sensor: power_value
 time_unit: min
 accuracy_decimals: 5
 unit_of_measurement: "Wh"
 filters:
 - multiply: 0.0166666666666667

 - platform: integration
 name: "Total Current Consumed"
 id: total_current
 sensor: current_value
 time_unit: min
 accuracy_decimals: 5
 unit_of_measurement: "Ah"
 filters:
 - multiply: 0.0166666666666667

This YAML configuration snippet provides all the necessary data for our planned testing of the GGreg20_V3 radiation sensor module in terms of power consumption during operation under normal background radiation conditions.

Measurement process

The power consumption was measured every minute, with data accumulated for previous periods. The test lasted for an hour, which allowed us to obtain the real consumption of the GGreg20_V3 module for 60 minutes for each of the three supply voltages.

The Home Assistant platform was used to collect and record sensor data. It also provided tools for creating visual graphs of electricity consumption.

Results and conclusions

Thanks to the testing, we have obtained detailed data on the power consumption of the GGreg20_V3 module at different supply voltages. These results allow users to optimize the power consumption of their DIY projects using this module.

Power supply with a voltage of 3.3V

Power supply with a voltage of 3.7V

Power supply with a voltage of 5.0V

Summary of results

The power consumption of the GGreg20_V3 module was tested for 60 minutes at different voltages under normal conditions. INA219 measurement update cycle: 1 minute

Test dates: 27.08. – 31.08.2023

No deviations in radiation level measurements were observed during testing

Testing was performed in the default settings of the GGreg20_V3 module. The buzzer is enabled. The Schottky protection diode is installed. Blue power supply LED lights constantly. The supply voltage remained unchanged throughout the test cycle.

Appendix. Theoretical battery discharge diagram

We also decided to show the theoretical discharge graph at three different voltages when the GGreg20_V3 module is powered by batteries of different chemistry and capacity.

The basis for our calculations was the battery characteristics available on the Internet:

However, please note once again that this graph is a theoretical assumption and does not take into account the discharge of real batteries under load over time and changes in voltage and current consumption during discharge.

About GGreg20_V3

The Geiger counter module GGreg20_V3 manufactured by IoT-devices, LLC is the company’s flagship product, which has found its users in more than 30 countries.

All over the world, radio amateurs use GGreg20_V3 to create their own DIY projects, learn and conduct experiments related to radiation measurement.

When developing this product and improving it since 2020, we tried to make the module compact, ready-to-use, compatible with as many DIY platforms and systems as possible, undemanding in terms of power supply voltages, easy to program, and harmonized in terms of operating characteristics with various Geiger tubes.

We have also developed a number of examples and posted them on GitHub for various hardware and software platforms such as Arduino UNO, ESP32, ESP8266, Raspberry Pi Pico W, NodeMCU, ESPHome, Tasmota, MicroPython, Home Assistant.

And we, at IoT-devices Company, hope that our Customers will have a great user experience and real pleasure by implementing this module in their projects.

We also thank everyone for supporting and choosing this product designed and manufactured in Ukraine. We really appreciate it!

Keywords

Geiger counter

GGreg20_V3

Testing of energy consumption

DIY-projects

Home Assistant

Raspberry Pi Pico W

ESPHome

INA219

NodeMCU

ESP8266

I2C

WiFi

YAML

If you have encountered the same situation after updating your ESP32 devices with ESPHome firmware, we recommend that you check out our repository, which already contains a description and workaround for the issue. Here is the way to go:
https://github.com/iotdevicesdev/GGreg20_V3-ESP32-HomeAssistant-ESPHome

We also invite you to read the discussion on GitHub:
https://github.com/iotdevicesdev/GGreg20_V3-ESP32-HomeAssistant-ESPHome/issues/5

Best Regards,
IoT-devices Team

The DCDC_3V3_400V_V1 module is a high voltage source for powering a wide range of Geiger-Muller tubes with different anode-cathode voltage levels, and can also be used as a low-power high voltage source in other DIY projects.

The need to set different output voltage levels is one of the reasons for installing a tuning potentiometer in the module.

The other adjustment components are resistor R1 and capacitor C1.

For explanation, please see the block diagram below.

The left part of the block diagram shows the structure of the high-voltage converter DCDC_3V3_400_V1 module.

The right part of the block diagram shows the components of the power consumers from the DCDC_3V3_400_V1 module integrated into the DIY project, according to the user’s design.

The output cascade of the DCDC_3V3_400_V1 module is a high-voltage multiplier. In projects of radiation detectors based on the Geiger-Muller counter, the tube receives a high voltage of 300 to 2000 volts through the R1C1 circuit.

The resistance, capacitance and voltage values for R1 and C1 depend on the type of tube or DIY circuitry. For this reason, R1 and C1 are not installed on the DCDC_3V3_400_V1 module.

Another reason for the absence of R1 and C1 on the module is the possibility of damage (electrical breakdown) of C1 when adjusting the voltage with a potentiometer.

Taking these factors into account, we recommend that when testing the DCDC_3V3_400_V1 module, you solder or connect a circuit to the output contacts according to the following scheme:

The voltage adjustment and measurement should be performed similarly to the steps described in the Initial Diagnostics Manual for the Geiger counter module GGreg20_V3.

Before you begin

1. The components of the device contain dangerous voltages. Do not violate safety precautions and rules for handling electrical installations.

2. To maintain the warranty of the device, users are not allowed to adjust the potentiometer themselves. To make changes to the module settings, please first obtain authorization and instructions from the support team.

3. Please note that if you use a conventional voltmeter (not the one required by this manual) to measure high voltage on the GGreg20_V3 module, the measurements will be inaccurate and insecure. Often, inaccurate measurement and adjustment leads to the device being inoperable or damaged.

Please do not attempt to measure high voltage with inappropriate tools.

A conventional voltmeter may show 150V, while the real voltage value may reach 500V, which is guaranteed to damage the module or tube. The multimeter can also be damaged.

Also, a conventional multimeter may not have the necessary speed to convert the analog values being measured.

And finally, note that high voltage measurements are performed on a capacitor, so do not forget to give it time to charge before the next measurement.

Getting started

1. Disconnect the module from the MCU board and provide power to the module via the corresponding connector on the module (BAT).

2. Inspect the detector board with a magnifying lens for damaged components.

3. Check the input DC power supply voltage Upower_supply that is supplied to the module. The input DC voltage must be between 3.0 and 5.5 V. The power supply must be at least 5 watts (1 amp at 5 V).

4. Check whether the J305 tube is properly mounted on the holders. Caution! The electrodes of the tube and some other components may contain dangerous voltages for a long time after switching off.

5. Turn on the GGreg20_V3 detector module without the case to access the diagnostic points.

6. The blue LED lights up normally.

7. The red LED does not blink (the buzzer does not beep, there are no pulses at the output, even with a jumper).

1. Tools needed

Note: Alternatively, a multimeter with the above characteristics can be used. However, an oscilloscope will be much more convenient for this task.

2. Diagnostic actions

Objective: to obtain data on voltages:

• on the module’s power supply points (low-voltage part);
• on the module’s elements of the high-voltage part.

2.1 Diagnostic points

2.2 Low Voltage Measurement

2.2.1 Make sure that the DC voltage level of U5V at the point shown in the Fig. is 5V +-5%.

2.3 High Voltage Measurement

2.3.1 Set up the oscilloscope and probe as follows:

– Select the input channel, set the mode to DC, 10 volts per division.

– Set the switch on the probe to the 1:10 position.

– Sampling rate (number of signal points per unit time): 1 division per 1 second.

– Set the function of fixing instantaneous maximum voltage values.

2.3.2 Carefully connect the oscilloscope’s GND pin to the module’s GND. To do this, point the GND pin (or solder a wire) to the point “GND” shown in the Fig. Measure the voltage level at the point shown in the Fig. with a probe.

2.3.3 Make several measurements of U400V. Between measurements, pause for 5-10 seconds, which is necessary to restore the capacitor charge level. Observe on the oscilloscope screen the waveform of the capacitor discharge by the input resistance of the oscilloscope and the measured maximum voltage values. The correct voltage value should be as follows: 380 +- 40 volts for J305 tube.

Warning:

a) A voltage of 400 volts is dangerous to the human body.

b) Inaccurate positioning of the oscilloscope probe at the measurement point may cause damage to other components.

3. Observed Data Collection and Reporting

Please contact our support team with the measurement results (Upower_supply, U5V, U400V). We will provide additional instructions.

We have previously written about how to calculate the coefficients for the SBM20 tube and the J305, tube that come with our Geiger counter module GGreg20_V3 for DIY / IoT projects.
However, in those articles, we focused heavily on the calculation formulas and almost overlooked a very important detail: when calculating the conversion factor for the Geiger tube pulse count, we need to be aware of what exactly we want to get as the output.

If we need to obtain the radiation power of a radioactive source registered by the counter, this is one task.
It is a completely different task when we need to obtain the equivalent value of the radiation dose absorbed by the human body over a certain period of time.

We describe in detail how to calculate the coefficients in our previous publications, so we will not waste the reader’s time now.
Instead, we will try to show the differences between the calculated coefficients and how best to use them for a DIY project.

The data is provided for the J305 tube. Any other Geiger tube, such as the SBM20 or LN712, can also be used in its place, since they all have a similar principle of operation except for certain nuances that we can neglect for the purposes of this discussion.

In our previous publications, we went from start to finish: we have pulses -> we want to keep the value in μSv/h.
Today we will try to go the other way: from the goal of the DIY project through the sequential steps to achieve it.

As DIY Geiger counter users, we would most likely want to have access to the following information on our device’s display:

1. CPM: The number of registered pulses per minute received from the counter;
2. μSv/h: The radiation power of the source registered by the counter;
3. μSv: The absorbed dose by the human body over a certain period of time.

Take a close look at these values. The secret to calculating them correctly lies not only in the correct formulas and coefficients, but also in understanding the overall process:

• The source emits radiation;
• The counter registers it;
• The human body absorbs it.

The human body does not absorb everything that the counter registers. The counter readings and the absorbed dose are highly dependent on many factors. Therefore, to simplify the measurements, it is common to use ready-made data from the manufacturer and equivalent models for calculating the corresponding coefficients.

Pulse Count

We obtain the pulse count from the Geiger counter module. For convenience of calculations, as well as based on the pulse density during normal background radiation measurements, this parameter is best calculated in counts per minute (CPM).

For example, the J305 manufacturer specifies in the datasheet that the tube should emit 25 pulses per minute under normal background radiation. In other words, 25 CPM.

Why do we need the CPM value on the display if there are other, more understandable indicators? Indeed, it is possible to do without pulses per minute. However, it is a very convenient indicator when we want to understand if there are any malfunctions in the device. Usually, in our devices, we make a cumulative counter of the number of registered pulses for the entire time the device has been operating since the power was applied.

In this case, even if we do not have a source of accurate synchronized time, such as NTP or RTC, we can still calculate the average number of pulses per minute by dividing the sum of all pulses by the total time elapsed since power was applied. This indicator can indicate the quality of our data, even if hours have passed since the device was turned on.

We hope that since the principle of such checks is already known to you, you will develop your own algorithms for checking the data quality and the operation of the counter if necessary. There can be many implementations.

Radiation Source Power

When we want to estimate the radiation source power, we need to apply the conversion factor from CPM to μSv/h obtained by calculation based on the data specified in the tube’s datasheet from the manufacturer:

For the J305 tube, the manufacturer specifies a sensitivity of 44 cpm per 1 μR/h from a Co-60 source;

Let’s convert the data we need:

1. Converting to counts per minute at 1 mR/h:

CPS / mR/h → CPM / mR/h: 44 * 60 = 2640;

2. Converting to counts per minute at 1 μSv/h:

CPM / mR/h → CPM / μSv/h: 2640 / 10 = 264;

3. Value of one pulse per minute in μSv/h:

1 / ( CPM / μSv/hr ) = 1 / 264 = 0.00378;

Therefore, if we need to convert the pulses registered by the J305 tube during a minute to μSv/hour and obtain the radiation source power value:

1 CPM = 0.00378 [μSv/h];

or

When we read the documentation for a Geiger tube, this is the parameter that is usually discussed.

Equivalent Dose Absorbed by the Human Body

To obtain the value of the equivalent dose of radiation absorbed by the human body, we will apply the model of a human body phantom:

1. Lets convert counts per second to counts per minute at 1 mR/h:

44 * 60 = 2640 pulses/minute / mR/hour

2. Convert CPM at 1 mR/h to CPM at 1 R/h:

2640 * 1000 = 2640000

3. Let’s find the value of the exposure dose R/h at 1 CPM:

1 / 2640000 = 0.0000003787878788

4. Find the air-kerma (Ka, kinetic energy released per unit mass/in matter):

The equation is as follows:

Ka [Gy] = 0.00877 [Gy/R] x exposure [R]

where 0.00877 – radiation dose absorption coefficient by the human body on a phantom model under the influence of photon energies of 100 keV – 3 MeV

0.00877 * 0.0000003787878788 = 0.000000003321969697 Ka[Gy]

5. Let’s convert Ka[Gy] to Ka[μSv] (i.e., from Gray to μSv):

0.000000003321969697 * 1000000 = 0.003321969697 Ka[μSv]

Thus, the formula for the equivalent absorbed dose of radiation by the human body for the Geiger-Muller J305 tube with gamma sensitivity for Co-60 of 44 cps/mR/h is as follows:

Please note: To obtain the cumulative value of the equivalent dose of energy absorbed by the human body, we need to add the hourly values to the previous accumulated sum throughout the entire measurement period (from the moment of power supply or resetting the counter value). See the example below.

Why should we be more interested in the dose of radiation absorbed by the human body than in the radiation source power? There are at least two reasons for this, which follow from each other.

First, from the point of view of radiation safety, it is not the power of the source itself that is important, but the dose that we will absorb over a certain period of time if we are exposed to the radiation source.

Second, since the dose of absorbed radiation is so important, it is the dose for humans that is calculated and provided by government organizations for radiation protection and public health.

Usually, the permissible dose is given for a period of one year. It is such tabular data that allows us to objectively assess what is the normal level of background radiation – the moment when the radiation source power and the equivalent dose absorbed by the human body can be converted to common units and compared.

If the normal background level, in terms of its instantaneous power converted to a year, turns out to be higher than the permissible dose per year, then this may not be background, but a certain radioactive source. And then something needs to be done immediately with the radiation source that creates such a “background” so as not to exceed the permissible absorbed dose of radiation by our body.

Practice and Examples

Now we come to the most important thing: when creating sensor entities for GGreg20_V3 with a J305 tube, for example in ESPHome, we need to use the appropriate coefficients for different physical values.

1. Number of pulses per minute is always just the number of pulses – a dimensionless value. But if necessary, a conversion or averaging coefficient can also be applied (not considered in this article);
2. For radioactive source power: CPM * 0.00378 [μSv/h];
3. For the equivalent dose absorbed by the human body: CPM x 0.00332 [μSv/h], finding the sum of the minute-by-minute values [μSv] for the entire measurement time.

Example for ESP32 + GGreg20_V3 + J305 у ESPHome

# 1. Pulse Count Sensor from a Counter with a 60-Second Measurement Cycle

 sensor:
- platform: pulse_counter
 pin:
 number: 23
 inverted: True
 mode: 
 input: True 
 pullup: False
 pulldown: False
 unit_of_measurement: 'CPM'
 name: 'Ionizing Radiation CPM'
 count_mode: 
 rising_edge: DISABLE
 falling_edge: INCREMENT # GGreg20_V3 uses Active-Low logic
 use_pcnt: False
 internal_filter: 180us # for J305
 update_interval: 60s
 accuracy_decimals: 0
 id: my_cpm_meter

# 2. Radiation Source Power Sensor with a 60-Second Measurement Cycle

- platform: copy
 source_id: my_cpm_meter
 unit_of_measurement: 'uSv/Hour'
 name: 'Ionizing Radiation Power'
 accuracy_decimals: 3
 id: my_power_meter
 filters:
 - multiply: 0.00378 # for J305

# 3. Sensor for Equivalent Dose Absorbed by the Human Body per Hour with a 60-Second Measurement Cycle

- platform: copy
 source_id: my_cpm_meter
 unit_of_measurement: 'uSv/Hour'
 name: 'Ionizing Radiation Equivalent Absorbed Energy'
 accuracy_decimals: 3
 id: my_dose_meter
 filters:
 - multiply: 0.00332 # for J305

# 4. Cumulative Equivalent Dose Absorbed by the Human Body from Radiation Since the Start of Measurement (i.e., from the Moment of Power Supply)

- platform: integration
 name: "Total Ionizing Radiation Equivalent Absorbed Energy Dose"
 unit_of_measurement: "uSv"
 sensor: my_dose_meter # link entity id to the pulse_counter values above
 icon: "mdi:radioactive"
 accuracy_decimals: 5
 time_unit: min # integrate values every next minute
 filters:
 # cumulative absorbed dose. Converting it from uSv/hour into uSv/minute: [uSv/h / 60] OR [uSv/h * 0.0166666667]. 
 - multiply: 0.0166666667
 # but if my_dose_meter in CPM, then [0.00332 / 60 minutes] = 0.000055; so CPM * 0.000055 = dose every next minute, uSv.
 #- multiply: 0.000055 # for J305

Conclusions

In this article, we made an important discovery that the coefficients for different tasks for the same Geiger tube should be different. This approach differs from the examples that are given on the Internet.

Although we have already written in passing about different coefficients (see articles on calculating conversion coefficients), in our numerous examples on GitHub , we previously used only one coefficient, because that’s what everyone does.

Now we believe that it is better to calculate a separate coefficient for each sensor entity depending on its type and purpose. Perhaps we will even update the YAML files in our examples on GitHub.

References to other publications and examples

UA: Geiger tube J305: How to calculate the conversion factor of CPM to μSv/h Technical note
EN: Geiger tube J305: How to calculate the conversion factor of CPM to μSv/h. Technical note

UA: Технічна нотатка: Як розрахувати коефіцієнт перетворення для трубки Гейгера СБМ20
EN: Technical note: How to calculate the conversion factor for Geiger tube SBM20

UA: Трубки Гейгера-Мюллера: порівняння SBM20, J305 та LND712
EN: Geiger-Muller tubes: Comparison of SBM20, J305 and LND712

EN: DIY Geiger counter GGreg20_V3 on GitHub

Easy Links

Unique Vendor ID: https://go.iot-devices.com.ua/ggreg20_v3
User Friendly ID: https://go.iot-devices.com.ua/geiger-counter

Where and how to order

Website Online Shop
Etsy Store
Tindie Marketplace

But its main advantage is that it works via the I2C bus.

Why these thermometers are underrated

Someone may say that LM75 is not the best sensor in terms of its technological features and design as a chip. Indeed, there are many other types of temperature sensors, such as 1-Wire Dallas DS18b20. These sensors have a one-wire connection and many other design advantages, such as waterproof metallized capsule-shaped housings, etc. It is possible to connect many thermometers to the 1-Wire bus on a single wire, 1-Wire supports error detection and device identification, etc.

But the 1-Wire bus has one and the most important drawback – there are no other devices for this bus except thermometers. That’s not exactly true, they are produced, but it’s such an unpopular segment that they are impossible to buy.

When we need to build a device of medium complexity, such as a weather station, several different sensors and other peripherals need to be connected to the main controller (a list, for example):

• BME680 / BME280 I2C / SPI;
• DS18b20 1-Wire;
• SPI / I2C display;
• Lightning sensor AS3935 SPI / I2C;
• Light sensor MAX44009 I2C;
• Temperature and humidity HDC1080 I2C;
• CCS811 I2C sensor;
• SCD4X I2C sensor.

And even with the powerful ESP32 (not to mention the ESP8266 and similar controllers, such as Arduino or RPI Pico W), we will have to solve the problem of optimizing the number of interfaces and protocols. After all, the processing of several different protocols will sooner or later affect our development and will require simplification not only on the hardware side (budget of free I/O ports), but also the software implementation of drivers for different protocols and interfaces that must run in parallel in the main loop of the controller.

Note. We are not writing about SPI here, because it is a specialized protocol with a completely different purpose and strengths that apply only to exceptional situations when it comes to sensors.

Therefore, in our opinion, you should choose solutions that can be easily expanded and operated in the future. 1-Wire and SPI devices are not well suited for such requirements and therefore we recommend not considering them unless it is absolutely necessary (as in the SPI case for high-resolution displays or measuring values at near real-time speeds).

It is worth trying to build an optimal hardware and software solution – we take a step towards the I2C bus. That is, since we will have an SSD1306 display with I2C on the main controller, an I2CUI4_V1 keypad with I2C, why would we need to install temperature sensors with any other interface? – So we decided to use only the I2C bus. All connections will be made through the I2CHUB_V1, splitter/hub, which supports the connection of 5 devices to the controller at the same time.

Note. As a reminder, I2C is a great bus – it not only allows you to connect many devices simultaneously, but also provides the ability to identify devices on the bus, control erroneous data, and hot-swap (connect and disconnect devices by the user on the go).

Built-in drivers in ESPHome

However, when we search on the ESPHome website, it turns out that the LM75 sensor, which we were going to use in the project as a thermometer, is not supported – there is no built-in driver.

We begin to do our own little investigation into the available drivers in ESPHome for temperature sensors like the LM75 ($0.89 USD on Mouser). And we find out that there are two other thermometers for which a built-in driver is already written in ESPHome:

• MCP9808 (1.39 USD on Mouser)
• TMP1075 (0.74 USD on Mouser)

Both sensors would have suited us technically. They are available on Mouser and other similar platforms. But we could not find ready-made modules with these chips at a price that would be close to the price of modules with LM75.

We thought that this was not acceptable to us, as it would not be to most of our readers. Given the similarity of these chips, no one wants to overpay 5-10 times for a thermometer module if you can buy an LM75-based module in every store.

Interestingly, the TMP1075 sensor is compatible with the LM75 specification (this is clearly stated in the datasheet), which is de facto the industry standard. Therefore, we concluded that we could try to connect our LM75 thermometer with the drivers for TM1075 that are built into ESPHome.

Unfortunately, we failed to make such a connection, even though the addressing on the bus and the internal registers are identical for the mentioned sensors. The only difference is that the TMP1075 also has a special identification register, which the LM75 sensor does not have. But even attempts to make changes to the sensor type checking at the CPP-code level of this driver did not allow us to use it with the LM75 chip.

Note. To be honest, we still don’t understand why the developers and contributors of ESPHome haven’t made a built-in driver for the LM75 yet. We wouldn’t have to write this article and spend a lot of time doing strange experiments.

So we went back to the starting point and did what we should have done from the very beginning.

Connecting the driver externally

As you probably know, ESPHome has at least two mechanisms for connecting custom device drivers from the outside: Custom Component and External Component.

Custom component is currently considered an obsolete integration option and is not recommended by the ESPHome documentation.

Instead, the documentation recommends using another, alternative way, which in our opinion is currently the only, easiest and best way to perform driver integration yourself – External Component.

The difference of the External Component is that the ESPHome user does not manually write interfaces for data flows from the sensor through low-code roundabouts, but uses fully defined mechanisms, which, by the way, are also used by all other ESPHome components:

So, to connect an External Component, you first need to describe its mapping correctly. We won’t dive into the details of programming and configurations here, because we found a ready-made component for the LM75 on GitHub.

To add LM75 sensors, you only need to add a few lines to the YAML configuration of the device in ESPHome:

• connect an external component (External Component):

• add LM75 sensor entities:

For convenience, we have forked the esphome-lm75 repository provided by https://github.com/btomala on GitHub to our account https://github.com/iotdevicesdev/esphome-lm75

An example of how the connection of LM75 drivers for the ESP12.OLED_V1 controller manufactured by IoT-devices, LLC looks like in ESPHome:

# YAML Config Example
esphome:
  name: esp12oled-lm75
  friendly_name: esp12oled-lm75
  comment: "Configuration example of two LM75 for ESP12.OLED_V1 with ESPHome firmware"
  project:
    name: "iot-devices.esp12oled-lm75"
    version: "1.0.0"


external_components:
  - source: github://iotdevicesdev/esphome-lm75
    components: [ lm75 ]


esp8266:
  board: nodemcuv2


logger:


api:
  encryption:
    key: "8tDDLc3S5dnSjADItGR5+7KxoUBhUIqeOiJZIXy"


ota:
  password: "c15e9a44e1408352d945b8cd35b79"


wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password


  ap:
    ssid: "Test-Node Fallback Hotspot"
    password: "rtF1XxDZ9"


captive_portal:


i2c:
  sda: 4
  scl: 5
  id: i2c_bus


sensor:
  - platform: lm75
    id: temperature
    name: "LM75 temperature"
    update_interval: 30s
    address: 0x48


  - platform: lm75
    id: temperature2
    name: "LM75 temperature2"
    update_interval: 30s
    address: 0x49
# END YAML Config Example

Note. This code is also available on our GitHub: github.com/iotdevicesdev/ESP12.OLED_V1-LM75-ESPHome

Project components

1 x ESP12.OLED_V1 module with ESPHome 2023.12.5 firmware;

1 x I2CHUB_V1 module:

1 x LM75 module (no brand);

1 x CJMCU-75 module.

Project results

This is the main thing we wanted to tell you in this text:

1. We have connected the LM75 via the External Component mechanism so easily and simply that we could not believe it ourselves after some complicated experiments with the TMP1075 driver.
2. The dependencies are pulled directly from GitHub, or can be linked from a local repository on your ESPHome/HomeAssistant drive. The External Component connected in this way is automatically included in the firmware during its compilation.
3. We have verified that there are no problems with addressing multiple LM75 sensors simultaneously with this component.
4. It’s as simple as connecting a sensor with a built-in driver like BME280 to ESPHome. The simplicity of using an off-the-shelf component via the External Component method is nothing compared to using the obsolete Custom Component method that we used to do for our other applications with the VEML6070 UV sensor.

As you can see in the following screenshots, our project has been successfully completed:

• LM75 is connected to the ESP12.OLED_V1 controller with ESPHome firmware;
• Two LM75 sensors work simultaneously with the main controller. Where two sensors work, eight can work (if necessary, the LM75 has three I2C address pins, which allows you to work with eight sensors on each I2C bus at the same time);
• The data from the sensors is sent to Home Assistant and displayed on the Dashboard;
• Further, the sensor values can either be displayed independently on the ESP12.OLED_V1 controller display using the ESPHome firmware, and/or can be used in Home Assistant automation scenarios.

LM75 sensor values on the Home Assistant server Dashboard:

Graphs from the Home Assistant server’s Logbook:

LM75 sensor values in the Developer Tools menu of the Home Assistant server:

Screenshots of the ESPHome console:

• Devices found during I2C bus scan (display and two thermometers)

• Drivers for LM75 sensors initialized

• ESPHome receives sensor data and transmits it to Home Assistant

That’s all we have planned to discuss on this topic for now.

Thank you for your attention!

Good luck!

When we developed GGreg20 in 2020, we did not know anything about these things at all. Now we can share our company’s experience with anyone who needs help or is just looking for more information

Please note that we are mostly comparing the SBM20 і J305 Geiger-Muller tubes, that the GGreg20_V3 comes with, and the LND712 tube is mentioned here as another alternative to both tubes. This allows us to extend the comparison to the capabilities of the more complex and expensive LND712 tube. Without such comparisons, this publication would have no depth and would be reduced to the thesis that SBM20 and J305 are interchangeable and therefore there is nothing to compare them.

Here are the key points to consider when choosing a Geiger-Muller tube for a DIY project:

• The purpose of the DIY project;
• Types of radiation that the tube can detect;
• Sensitivity of the tube;
• Internal noise and insensitivity;
• Operating voltage level;
• Dimensions and method of mounting the tube;
• Country of origin and year of manufacture.

Let’s consider and compare the tubes from these angles in more detail.

The purpose of the DIY project

The way you set the project goal may determine what success criteria you will use to measure the results you have or have not achieved.
With the Geiger counter, the project goal can also be very different.
For example:

• a cheap stationary device that should measure background radiation and alert you to danger most of the time;
• a miniature pocket device as a personal safety sensor for hiking;
• a sensitive and high-speed meter for detecting radiation in food and other materials;
• a meter/signalizer for radioactive gases in the air, such as household radon.

The task for which the end device is being developed may require the selection of a tube in terms of size and not require high sensitivity at all, etc. Therefore, only the user can determine for himself which tube in the Geiger counter is suitable. We can only point out that the selection of a tube according to the project task is a complex multifactorial analytical process, which we have tried to describe in depth in this publication.

Types of radiation

It is quite simple: you need to choose a tube depending on what radiation you need to measure in your project.
Most common tubes are sensitive to gamma and beta radiation. Some tubes are also capable of measuring the alpha channel.
Please note that the alpha channel in tubes is usually realized by having a mica window in the end of the housing.
To convert an a,b,g-tube to a b,g- tube, it is enough to close the mica window tightly with a piece of paper or the plastic cover of the housing.
To turn a b,g- or a,b,g- tube into a g- tube only, you need to shield the tube from beta particles. This can be accomplished by an aluminum casing with a thickness of several millimeters. Such an aluminum casing shields the tube from both beta and alpha particles at the same time.

As far as this article is concerned, the SBM20 and J305 tubes are capable of measuring beta and gamma radiation. The LND712 tube has all three channels: alpha, beta, and gamma.

How can this affect a DIY project from a practical point of view?

If you plan to measure only gamma rays with the SBM20 / J305 tube, then you need to shield such a tube from beta particles.
If you need to measure only beta particles with the SBM20/J305 tube, then you can try to use two such tubes at the same time: one with a shield that protects against beta particles, and the other without such a shield. In this case, by finding the difference between the measurement results for each tube, we can calculate the quantitative characteristic for beta particles.
The same applies to alpha particles: by filtering the alpha channel and subtracting the results between the tubes, we find the quantity for alpha particles.
With the LND712 tube, which is sensitive to a,b,g-, it is possible to implement a project to measure household radon, in particular Radon-222, since this isotope is the source of alpha particles.
It should be emphasized that for measurements with several tubes, you need to have several GGreg20_V3 modules. Each module is connected to a separate GPIO of the main controller, which in turn will be able to count pulses independently for each tube.

Tube sensitivity

When we first started to figure out which tubes to use for our GGreg20 Geiger counter project a few years ago, we experimented and sometimes mistakenly chose tubes that were capable of producing only a few pulses per hour at background radiation levels.

Of course, they would be impossible to use in a DIY Geiger counter project, which should be sensitive enough to measure background radiation most of the time.

So, when you are choosing which of the GGreg20_V3 options to order, don’t worry and know that we have already tested different tube models for you and have included in the options only those that really work with the GGreg20_V3.

J305 and SBM20 tubes, although they have some differences, work equally well with our product.

The LND712 tube, although not currently available as an option for the GGreg20_V3, also works very well with our Geiger counter module..

In general, the LND712 has a lot of interesting functions and features that can make a project with the GGreg20_V3 module even more interesting. Perhaps in the future we will offer this tube as an additional option as part of the Geiger counter module of our production.

In terms of sensitivity (pulses/mR), the LND712 tube is not much different from the SBM20, but given that it is more modern, we would prefer it

Own noise and insensitivity

Geiger tubes have two important characteristics that should be taken into account when comparing them.

Internal noise is the false-positive pulses generated by the tube in the absence of external radiation. When designing or calibrating a tube, the manufacturer places the test sample in a radiation-shielded laboratory environment and measures the number of false-positive pulses per unit time. Typically, the intrinsic noise of the tube is specified in the datasheet in pulses per second.

The SBM20 tube, compared to the J305 and LND712, has a significantly higher intrinsic noise value according to the datasheet. This means that the SBM20 tube will measure natural background radiation much worse than the J305 or LND712 tubes.

Insensitivity is the time during which the tube recovers from the previous avalanche-like disturbance and is unable to detect the next such event. This time is commonly referred to as the dead time of the tube and is measured in microseconds. In practice, as a consequence, the tube is not able to generate an output pulse during this period of time.

It is also worth noting that the dead time directly depends on the size of the tube. The longer the tube is, the longer this time is. Of course, the length is not the cause, but only a consequence of the general design of most tubes and their principle of operation.

If your project is aimed at measuring high levels of radiation, this property of the tube must be carefully considered, because the higher the radiation we measure, the more dense the events that the tube records will be. At a certain point, the limit will be reached beyond which insensitivity will begin, i.e., the density of events in time when the tube simply does not have time to recover to register them.

Due to its size, the LND712 tube (90 microseconds) is the leader in this indicator, which is half that of the SBM20 and J305 tubes (190 and 180 microseconds).

Note. Here we present the Dead Time for J305 based on the data from the Internet, since the datasheets from suppliers do not contain this data.

Sensitivity to UV. It is worth mentioning the sensitivity of glass-bodied tubes (such as J305) to the rays of ordinary sunlight, especially to the UV spectrum. Indeed, you can find videos of experiments with a UV flashlight and ordinary sunlight on the Internet. The tubes in those videos are just going crazy from these stimuli, which can be seen with the naked eye.

We also conducted a quick test. We were unable to reproduce the behavior of J305 shown in the video. It is possible that the tube that generates false-positive events in the video from the Internet has some physical or technological defects that cannot be identified without special equipment.

We sympathize with the owner of such a tube. And because of this, we decided to test random samples from a batch of our J305 tubes, which are supplied as an option to the GGreg20_V3 module. Although our J305 tubes did not show such an effect, we fully agree that sunlight can create additional noise in measurements. We recommend placing the J305 tubes in a light-tight enclosure if possible.

With the Geiger counter module GGreg20_V3, we offer (as an option) a protective cover printed on a 3D printer. Although this cover is not able to act as a full-fledged shield for the high-energy photon flux of sunlight, it will at least partially filter one of the sources of possible noise.

The level of operating voltage

When comparing the available tube options, keep in mind that different types of tubes may have individual supply voltage levels. This information is usually included in the datasheet for the tube.

In practice, it is also important to keep in mind that the Geiger counter module (and its settings!) on which the tube you choose will be installed is crucial.

The GGreg20_V3 module was designed to be able to provide the widest possible range of operating voltages. On the one hand, the GGreg20 supports 200 – 1200 V in the high-voltage part. On the other hand, the module can be powered in the range of 2.4 – 5.5 V. As far as we know, this is the widest range of supply voltage among similar modules.

Therefore, in terms of high-voltage supply voltage, the GGreg20_V3 module supports all the tubes we are reviewing and comparing: J305 (380V for the model with a glass tube), SBM20 (400V), LND712 (500V).

In practice, beyond the scope of this material, we advise you to always pay attention to whether the module that will work with the tube allows you to adjust the voltage required for the tube to work. Exceeding the supply voltage of the tube is guaranteed to damage it. If the voltage is too low, the tube will simply not work.

Dimensions and method of mounting the tube

The J305 and SBM20 tubes have similar dimensions and a convenient mounting method that does not require soldering. From the point of view of manufacturing microelectronics for IoT devices, they are medium in size compared to other Geiger tubes.

SBM20 and J305 can be called interchangeable, because they have a similar operating voltage level, the same terminals, and almost the same dimensions, which allows you to replace the tubes with each other if necessary, if you can set the appropriate conversion factors for CPM.

It is particularly convenient that on the board of a Geiger counter module such as the GGreg20_V3, the mounting supports both tubes. It is also useful that the Geiger tube can be quickly removed from the module or replaced. In the case of the SBM20/J305, this is as easy as changing the batteries in a flashlight.

The LND712 has about half the length, which makes it ideal for the size of the a,b,g-radiation sensor. But its output pins are made in such a way that it only needs to be soldered. Therefore, LND712, paired with a much higher price, is no longer as “convenient” as SBM20 or J0305.

Sometimes, in order to adjust the settings of the Geiger counter module, you need to be able to remove the tube – in the case of LND712, this will be impossible without soldering.

It’s also worth noting that in the case of building pocket devices, the length of the tube can be crucial. Let’s see: the thickness of the device will also be affected by the battery, buttons, and connectors, so the diameter of the Geiger tube is leveled by these other limitations and does not affect the dimensions of the device body. However, the length of the tube requires an increase in the size of the device body. For these reasons, the LND712 tube is significantly better than the SBM20/J305.

Country of origin and year of manufacture

In our opinion, the country of origin is no less important than the other characteristics of the tube. Even from a purely practical point of view (cost and time spent on logistics, supporting local businesses, paying taxes, etc.), it is better to buy a tube that is made in the United States.

Unfortunately, we are not aware of any opportunities to purchase tubes made in Ukraine. Our quick searches for Ukrainian tubes did not turn up anything..

If you know of any Ukrainian-made Geiger-Muller tubes, please contact us

The stocks of Soviet SBM20 tubes at private sellers are significantly depleted. The shelf life of the Soviet models has long since expired. That is why we are constantly looking for alternatives. One such alternative is the Chinese-made J305 tube. The J305 tubes sold on Alibaba and Aliexpress are of 2020-2022 production year and fully meet our requirements in terms of technical characteristics and quality.

LND712 tubes also have excellent specifications, quality, and functions. The only drawback is that they need to be purchased in the United States, with long logistics to Europe. Given the higher relative cost of these tubes and the lack of an organized official retail distribution network for LND712, it is clear why this tube has not been in the lead in the statistics of DIY Geiger counter projects.

Conclusions

We’ve been monitoring our own statistics for several years now, as well as those of projects like radmon.org, ThingSpeak, uRADMonitor, and others.

The Soviet-made SBM20 tube is probably the most popular among those used in DIY projects.

However, it is almost impossible to buy SBM20 anymore, as Soviet-era stocks are depleting, the shelf life and expiration date have expired, and the manufacturers of modern SBM20 tubes are only in a country that is under sanctions and is an internationally recognized aggressor, a sponsor of terrorism and is currently committing war crimes and crimes against humanity at least in Ukraine.

At the same time, the Chinese J305 is much easier to find and buy online, but only when it comes to the glass-body version. Unfortunately, J305 with a metal body is currently very difficult to buy for reasons unknown to us.

Unlike the SBM20 and J305, the American LND712 tube, in addition to beta and gamma, also has an alpha radiation measurement channel, which significantly expands its range of application in DIY projects. The LND712 tube has a metal body, like the SBM20, and a mica window for detecting alpha particles.

On Internet forums, users have suggested that the glass body of the J305 is not protected from photons of normal sunlight, which can interfere with the measurement process if the tube is not additionally protected by a sunproof cover.

We are not sure of this statement, although there is also some understanding on our part that glass tubes require a sunproof cover as glass can transmit light, including noise, which can increase the noise level of observations.

Conversely, the metal housing of the SBM20 and LND712 tubes can act as a shield to a small extent for electromagnetic interference and sunlight. This makes the measurement performance of metal tubes more stable. On the other hand, a tube with a glass body may be more sensitive to radiation, which is also a useful property under certain conditions.

But it should be noted that all of these are just assumptions that should be tested. However, we are not able to test all of this, because such tests require a specially equipped laboratory.

Besides, we always have a much better tool – the manufacturer’s datasheet. The tube must meet the characteristics and operate in the manner specified in the datasheet.

If we were choosing a tube for ourselves, we would not hesitate to choose the LND712. However, since GGreg20_V3 does not currently support this tube size, we would choose between SBM20 and J305 as follows:

• Shelf life – J305 is better;
• Internal noise – J305 is better;
• Sensitivity – J305 is better;
• Country of origin – J305 is better;
• Background radiation – J305 is better;
• Calibration source – J305 is better (most tubes are calibrated by Co-60);
• Dead time – no difference;
• Metal case – SBM20 is better;
• Dimensions and mounting – no difference;
• Supply voltage – no difference;
• Retail distribution network – J305 is better;
• Price and quality – J305 is better.

Guided by the data from the documentation, statistics from the Internet and our own experience, we would definitely choose the J305. We would choose SBM20 only in exceptional circumstances, when for some significant reason J305 would be impossible to use.

Thank you for your attention!
Team IoT-devices, LLC

Additional resources on the topic:

https://iot-devices.com.ua/en/ggreg20v3-geiger-tube-j305/
https://iot-devices.com.ua/en/technical_note_supply_voltage_range_geiger_counter_ggreg20_v3/
https://iot-devices.com.ua/en/uv-test-of-the-j305-geiger-tubes/
https://iot-devices.com.ua/en/technical_note_performance_of_diy_geiger_counter_ggreg20_v3_at_low_-temperatures/
https://iot-devices.com.ua/en/geiger-counter-emulator-ggreg20_v3-module-by-means-of-esp8266-part1/
https://iot-devices.com.ua/en/maximum-radiation-that-can-be-measured-by-geiger-counter-ggreg20_v3-en/
https://iot-devices.com.ua/en/ggreg20v3-case-3d-model-for-personal-use/

Easy Links:

go.iot-devices.com.ua

/geiger-counter
/high-voltage-converter
/geiger-counter-emulator
/tindie

We conducted our own quick UV test of Geiger tubes J305 , which are supplied as an option with the Geiger counter module GGreg20_V3, and filmed this video: .

.

As a result of the test, we determined that the J305 tube from our batch is not sensitive to UV 395nm (the flashlight we had on hand). At least, we were not able to reproduce/observe such sensitivity as in the video from the Internet.

We wondered what would happen if we took our DIY Geiger counter module GGreg20_V3 and put it in a freezer with a target temperature of -23 Celsius together with the ESP32 controller.

Will our sensor work at such a low temperature? Will we see any failures or deviations in the radiation sensor measurements?

My colleagues and I were betting that sooner or later we would get False-Positive pulses at the ESP32 input during strong cooling.

The fact is that when it comes to such a modular system, it may contain several points of failure that can show up during operation at low temperatures. Before starting the test, we considered the following as possible points of failure:

• the Geiger counter module board,
• the ESP32 controller board,
• the connections between them,
• and the Geiger-Muller tube SBM20.

Each of these components could stop working or become unstable due to deformation of materials, changes in the conductivity of wires and contacts, or the formation of dew or ice on the surface of the electronics.

Although the Geiger-Muller tube has an appropriate temperature rating (-60°C to +70°C) from the manufacturer, it can also change its behavior when exposed to low temperatures. For example, loss of pulse generation capability due to slowing down of molecular/electronic processes due to a decrease in the energy of particles in the gases filling the tube, or, conversely, avalanche-like ionization inside the flask due to the thermodynamic characteristics of these gases (Ne+Br2+Ar).

For this reason, it was interesting and important to conduct such a test of the GGreg20_V3 module and the circuit with the ESP32 controller that they create in DIY projects to answer potential questions from our users and customers who plan to use the GGreg20_V3 Geiger counter in harsh weather conditions.

We kept the sensor at such low temperatures for several hours. At the same time, we recorded measurements from the sensor by the Home Assistant server wirelessly and observed the measurement graphs.

And…. And we are satisfied with this test, but let’s not get ahead of ourselves and tell you how everything happened step by step.

So, in this experiment, we aimed to investigate the performance of a DIY Geiger counter module at low temperatures. We placed the Geiger counter module and ESP32 controller in a freezer with a temperature of -23 Celsius and kept it there for 5 hours. We recorded measurements from the sensor and observed the measurement graphs to evaluate any failures or deviations in the radiation sensor measurements.

We were also able to measure the temperature of the sensor during the test because we had a temperature probe on hand (1-wire DS18b20 12-bit). However, we also monitored the external temperature of the module box several times during the test using a non-contact infrared thermometer

Results

We did not notice any failure or deviation in the radiation sensor measurements during the entire test period. The measurements from the sensor remained within the normal background radiation during the entire test period.

We also used these practical tests to check how the system would behave during the transition from warmth to deep cold, as well as from the cold of the freezer to normal room conditions, and found that there were no problems that could be detected by simple monitoring tools. The absolute value of the temperature drop (sharp decrease and increase) during the test was more than forty degrees.

Discussion

Our results suggest that the GGreg20_V3 radiation sensor is capable of performing reliably at low temperatures. This is an important finding as it implies that the sensor can be used in low-temperature environments without any significant loss of accuracy or reliability.

However, it is worth noting that our experiment was limited in scope, and further tests may be required to confirm the findings.

In particular, we did not do any statistical verification of the obtained data, but only conducted several long-term (up to six hours long) experiments and practically checked whether the sensor and the microcontroller would work normally.

Conclusions

In conclusion, our experiment showed that the GGreg20_V3 radiation sensor can perform reliably at low temperatures. We did not observe any failures or deviations in the radiation sensor measurements during the entire test period, indicating that the sensor can be used in low-temperature environments without any significant loss of accuracy or reliability. However, further tests may be required to confirm these findings and evaluate the performance of the sensor over an extended period.

Now you also know what happens if the Geiger counter GGreg20_V3 is placed in a low temperature environment.

We hope that you found this post as interesting and useful as the experiment we conducted.