Ion Chambers and Geiger

Comments and ideas for the measurement of Radon and radiation

Two SBM-20 in parallel and a GeigerAdapter form a simple probe, very sensitive and inexpensive.

This image shows a measure of environmental fund with Theremino_geiger

More information
– Software download:
– Electrical schematics and Assembly plans:
– Hardware, DIY and kits:
– Images and videos:
– Article about Open Source Electronics:

In the documentation folder (accessible from the Help menu) you will find all the information you need to use the program and probes.

The HAL program, required to connect to the Master, you download from here:

Measure with Geiger

This image shows a measure of environmental fund 15 minutes, followed by the provision of a sample of dietary salt. At the beginning of each measure was pressed “Start”

Precision measurements you make with long integration time. While precision measurements you do not have to change the conditions of measurement. Move the samples during the measurement would be like taking a fever without taking the thermometer in the same spot for the three minutes required.

All ’ start of the measurement You should press the button “Start new measure” that is how “Reset the thermometer” Before measuring a fever. Without this initial zero setting it is likely that the fever has not indicated its, but someone else.


To make precise measurements You must respect the agreements with the program, the instructions are explained, in detail, the procedures to be followed.

To make quick measurements, just set the “usual” 2 or 3 minutes of integration, using all portable geiger..


Some users would like to avoid having to follow the measurement protocol. In essence they would like a button “Start” you press alone, any significant variation of the radioactivity.

Early versions of Geiger had this option, but we found that this made the measurements unreliable and bore, in some cases, completely wrong measures, without being able to inform the user ’ and without any possibility of control by software. These errors were not due to an inaccurate implementation of ’ algorithm, but are inherent in the measurement method and any appliance that is automatically reset can avoid them.

As far as l ’ algorithm is sophisticated and set the trigger thresholds, There are always a few sequences of changes that lead to a zero delayed, resulting in pollution of the first part of the buffer of integration, or to a non-zero or, even worse, to reset drivers, they do lose hours of data.

To miss any appliance that resets by itself, proceed as per the following example:

1) Let it settle to the bottom

2) Bring a sample very radioactive 20 cm so that it resets and empty the buffer

3) Continue moving the sample up to contact, but very slowly, so as not to over take the reset threshold.

The first part of the buffer will be filled with samples too low, the threshold it clicks more and the measure will continue to be systematically flawed, How long you have the patience to wait.

This example sequence is extreme, but there are many real opportunities to attract more or less large errors, If you allow ’ user to move samples at any time, or add and remove fragments in a sample already to an extent.

The devices designed for measuring “on the field”, where it is important to react quickly, are not suited to precision measurements and can, in many situations, provide incorrect measurements.

Measure with the ion Chamber

Ion Chamber documentation files do not show enough that, in some cases, the pulse rate can be very low.

In environments with little radon (d ’ summer with wind and opened Windows) Radon concentrations may fall under the 0.1 PCI/l (4 Bq/m3). In these cases, you get even less than one pulse every 5 minutes. It can also happen to not measure no pulse for ten or fifteen minutes. The randomness then back to place the media, concentrating many impulses in 10 minutes after. The next image shows this behavior.

In this picture have gone well 9 minutes, before receiving the first impulse. In the central zone is also a period of 15 consecutive minutes without pulses.

That is why we designed a very large room (from 1 liter). With many commercial appliances impulses would also 100 times less frequent. For example a “Safety Syren Pro3” (a few cubic centimetres), would produce on average, Pulse every 7 hours and could spend long periods, even more than a day, no pulse.

Test of Thoron

If you live in an environment with little radon, the low frequency of impulses might suggest a malfunction of the room. Fortunately there is a Thoron, a similar Radon gas, but much more convenient for testing. More information about the test of Thoron, on pages 21 and 22 of the document “Radon_IonChamberElectronics”, download from here: /hardware/inputs/radioactivity-sensors

In the first part of this picture you see the Environment Fund. In the second part the mantle containing Thorium was positioned in the saucer, and been pressed Start. In the third part, the Start button was pressed again and in a few minutes the measurement has stabilised at about 5 PCI/l. In just over half an hour ’ l ’ error fell to 10%.

The gas mantles containing thorium are not all the same and the room may not fill completely due to leakage between the saucer and the room. Then the measured value may be different, Come on 5 PCI/l of this picture.

If you measure from 2 PCI/l to 10 PCI/l the test passed, Otherwise please email us.

In this picture the mantle with thorium and saucer were removed. L ’ indoor air was grossly cleaned up, waving a cardboard for a few seconds. Then the Chamber was lying horizontally, so leave the holes open to both terminals and pressed the Start button. In just over half an ’ now the room is completely cleaned up and returned to 0.1 PCI/l.

The ion Chamber should always be handled with delicacy. The bursts of pulses that are produced when the room is shaken, mild vibrations are produced by central wire and do not indicate a malfunction. Even dust bunnies can cause bursts of pulses, You may need to add dust filters. Read pages 25 and 26 of the document “Radon_IonChamberElectronics”, download from here: /hardware/inputs/radioactivity-sensors

  1. Hayley Davis says:

    I finished the second of Livius h geiger for my grandson.
    The first one I keep for me.
    What is this theremino spectrum ? And’ a soft or is a module?
    Could you give me an explanation?
    Thanks friendliness de enzo

    Jane Davis- Trani-

    • Livio says:

      The Theremino_Spectrum is a software that performs “Gamma Spectrometry” (divide the gamma rays at various energies in order to find out which substances consist of radioactive samples – Caesium, Americium, Potassium etc…)

      Unfortunately the Geiger tubes are not able to distinguish the various energies from each other so it is necessary to use a Crystal scintillator and a photomultiplier tube (or other less expensive methods that we are studying)

      To power the photomultiplier and extract well its signal it also takes a special adapter module, as what you see in Blogs on mass spectrometry:

      Gamma spectrometry is a difficult area, Theremino_Spectrum software makes it simpler but hardware difficulties remain, and above all the difficulties of adjustment of the signal depending on the type of Crystal, the photomultiplier and value of high-voltage that is used.

      Put together everything you need is also quite expensive, PMT and Crystal can cost from 100 AI 300 Euro and it is difficult to choose the most suitable among the many existing types.

  2. Livio says:

    The new version of Geiger, developed in conjunction with GEMA Garcia, also measure the Radon and provides values in picocuries per liter and in Bequerel per cubic meter.

    Soon we will publish the ThereminoGeiger Version 3.0 and instructions for building a simple ion Chamber able to precisely measure small quantities as hundredths of picocuries.

    For now you can see how many picocuries is measuring the test installation on the site of Alessio:

  3. Mirko says:

    So to build a detector for Radon is simply a Master, one Geiger adapter and a room for ionization?

    Thank you

    You are doing a really good job.

    • Livio says:

      To build a detector for Radon is simply a Master and the ion Chamber with its small electronic circuit that does whatever it takes to connect it directly to a “Pin” standard of InOut Master.

      If you want, Alessio might give you a provisional scheme but I would recommend you to wait until the publication of this project so as to avoid many changes, trial and error.

      Hello and many good ions

  4. Mirko says:

    Thank you very much, I'm in no hurry I await your final version or almost. Thank you and I hope we don't get too many of ions :)

  5. Riccardo says:

    I wanted to ask you if you have done some tests with your geiger adapter and geiger bot ?


    • Livio says:

      The GeigerAdapter works fine with GeigerBot, We didn't try but there are users who have connected with no problems.

      On this page you will find how to connect the audio signal:

      In addition to the audio signal, you also find a 5 volt to power your GeigerAdapter, I think on some dell outlet’ iPhone 4 There is the 5 Volts, otherwise you will have to use 3 fleece mini touch-up 1.5 Volts to do 4.5 Volts or some small pile that produces from 3.5 Volts to 6 Volts. Even a one-element lithium would be fine (write to us if you need more detailed instructions for links)

      Do not add a switch on the battery, the GeigerAdapter consumes so little to minimally affect the discharge time. The batteries will last anyway 10 or 20 years and shatters for auto-download, not for the few uA GeigerAdapter charging.

      I have to though’ disappoint you on one thing, with GeigerBot you will not be able to measure very low levels of radioactivity (for example the few microsieverts products from a few grams of dietary salt) for various reasons: first of all the measurement time too short (120 seconds), then the lack of compensation of DeadTime, the lack of advanced filtering features and adjustable (FIR and IIR, Finite pulse response and Infinite Pulse Response) and finally the display too small that only allows a flat view (no lines min-max, scale settings, etc..)

      The GeigerBot also reads the impulses in software of the audio signal that fails to count impulses very frequent. Even under the best conditions and with UltraFast functions and Manual Setting enabled fails to count frequencies higher than approximately 5 or 10 KHz and this limits the measures approximately 1 millisieverts.

      You might think that 1 milliSievert is high enough for all the normal frequency measurement but the limitation has a much more serious side effect. Since the pulses arrive randomly even with very low levels of radioactivity it happens frequently that two pulses arrive very close together. In these cases the GeigerBot loses the second pulse with the result of measure less than real and less and less as the level of radioactivity increases. This non-linearity may be partially corrected by adjusting the DeadTime but it seems to me that the GeigerBot do not have this setting (I am not an expert on GeigerBot if I'm wrong correct me)

      Finally a small clarification, probably you know but I want to remember it for other users: with the GeigerBot, the GeigerAdapter and Geiger tubes can not distinguish the energies of the various isotopes, so no Gamma Spectrometry, only counts. For just a few euros and not spectrometry App on the iPhone but it also takes very expensive crystals and scintillator tubes that are not, not even used, for less than a few hundred euros.

      Here you will find lots of useful information about the characteristics of GeigerBot:


      If your intention is to make precision analysis with a portable instrument I would recommend you a tablet (to choose carefully, with a real USB port able to operate our Master, possibly ask us before) or a NetBook with Windows 7 and play it safe.

      If you want to make field measurements of radioactive minerals, on average, then the GeigerBot is fine and you are a very small and portable collection, not sensitive and not very precise, but always far superior to the old Geiger counters to steam.


  6. Mirko says:

    That's because I'm about to purchase the Master + Geiger adapter I would be interested in Android tablets, You can make this work?

    Having available a SBT-11A is to embed as a probe manually in your software?
    Thank you

    • Livio says:

      The master works on Android but only some tablet with Android have a real USB Host, also on Android none of our software works and I don't know when somebody’ time to let them go, If you can program in Android you should do it. Our software and’ all open source so someone or sooner or later he will’ but I don't really know what's going’ out and what reliability’ you will be able to’ get. My advice and’ to use a NetBook with Windows 7, so’ play it safe and everything works fine at 100%, audio and video applications, webcams, gesture recognition etc..

      To add the SBT-11A just open the file “Sensor_Data.txt” located in the folder “Extra” and add a line.

  7. Riccardo says:

    In “grip” of the various IPhone/IPod touch we have the 3.3 V, CMQ circuit can be used to bring them to 5V (I think if I insert a DC/DC at the entrance there should be no problem) or put the batteries; given the low fuel consumption was thinking two CR2032 (or two CR17355 occupying more space but with a much higher) in series?
    Also when will the circuit for bpw34? I'm guessing that have the same release of GeigerAdapter

    See you soon

    • Livio says:

      You can use a DC/DC or any battery also very small. I though’ wouldn't put two batteries from 3 Volt in series (in order not to increase the difficiolta’ mechanics) but one type lithium for model airplanes, a very small with the wires could be very easy to connect. You still do not exceed the 6 Volts and also not to invert the polarity’ and do the courts, the Theremino Adapter might hold up to this too but we do not attempt too fortunate… and then the batteries can heat up in an instant and even burst. To make sure you have protection against all could you put a resistor from 100 ohms on the positive battery wire – very close to the battery – in this way the current even if errors occur, reversals or breakages could never exceed a few dozen but it'd be quite sure.

      Unfortunately the research with the bpw34 aren't going forward, il PCB di prova e’ montato ma deve avere qualcosa che non va… non usciva niente e non ho molto tempo perche’ sto finendo il ThereminoMCA (Multi-Channel-Analyzer per la spettrometria gamma) e anche le camere a ioni per il Radon. Una volta che il software per la spettrometria sara’ finito riprendero’ in mano i BPW34, conto di metterne 10 in parallelo e usarli per la spettrometria, ti faro’ sapere….


  8. Robert says:

    Hello sirs,
    I’ve seen your page and I like very much your projects. I have 2 questions.
    1. Is the Gamma spectrometry module ready? Can I buy one?
    2. I can easily use the Theremino MCA software but I cannot use the Theremino Geiger. It seems it does not receive any signal. Do you have any advice?

    Thanks in advance

    • Livio says:

      Only the GammaSpectrometry software ThereminoMCA is ready the hardware not.

      Theremino Geiger normally gests signals from our GeigerAdapter via the module Master and the USB, but you can also use it with a audo signal with: Theremino_AudioInput that you can dwnload from this page

      If you do not use our hardware it is more difficult to setup all correctly, the audio signal must be clean, electronically coupled and not taken from a microphone. In addition the trimmings “TriggerLevel” and “Deadtime”, of the Theremino_AudioInput program, must be set properly.

      It is also very important to know hot to use the Theremino System Interprocess Communication based on SLOTS… and to set the same “SLOT” (maybe “1”)
      – in the CounterOUT SLOT of the Theremino_AudioInput
      – and in the Input SLOT of the ThereminoGeiger

      If you do not use the same SLOT the two programs can not communicate.


  9. luca says:

    How do I post to my homepage geiger data theremino , What is the correct writing which I have put in “FTP folder” to me pops up the following error:( Object reference not set to an instance of an object ) Perhaps lacks the ability to put the ftp port because my provaider the required?

    • Livio says:

      It must work, send me a picture with the error and with visible tab settings “LOG”
      If you still can't use my e-mail engineering (@) theremino (dot) com, or give me a phone number where call or a Skype.

  10. Livio says:

    Mirko wrote:

    Salve – I tried it today the adapter geiger + master with a sbm-20 and with the program geiger doesn't move leaf no account. The pipe definitely works I tested it on a geiger I have and it works normally. What am I doing wrong? – Thank you – Mirko

    As it may be of interest to all I say here with a mini guide.

    Checklist ( Checklist )
    Connect the pipe to GeigerAdapter
    – with the central pipe positive
    – with small and soft wires (Maybe one red and one black)
    – with the positive wire kept short

    If the tube is a LND-712 Add a resistor from 4.7 Meg
    in series with the positive and very close to the tube

    Connect the GeigerAdapter to pin 1 the Master with the black wire GND side

    Start with no open software.
    Check that there are one or more or Theremino_Geiger open or minimized.

    Connect the Master USB
    – must do “Bling-blong”
    – must blink green – very quickly
    – should Flash continuously – If you break or breaks no good

    Open the program HAL
    – in the first two lines should appear on Master and SlaveVirtuale
    – in the six following rows appear the six pins of InOut – one per line
    – If you do not already have set up all the pins like “Unused”
    – Configure the first PIN as “Fast Counter”
    – Set the first PIN the slot “1”

    At this point, with the single program HAL, It is already possible to test whether all is well

    Bring something radioactive or wait patiently.
    The count in column “Value” It must grow slowly – one unit for every tick of geiger. Possibly do double click on the line of the first pin and, in the test, enable the button “Beep on change” so you hear a beep for each count.

    Turn off the “Beep on change” and close the test.

    Minimize the program HAL but DO NOT CLOSE IT !!! (must remain active)

    Open the Geiger
    Launch the program ThereminoGeiger,

    Check that “Options”. “Communication slot”, “Entrance” is set to “1”

    Raise “Click volume” raise the Windows mixer

    The ThereminoGeiger must do Tick every incoming RADIUS.

    Measure with Geiger
    Choose the “sensor type”

    Set “Seconds FIR filter” to 9999 (3 hours)

    Place the radioactive sample as closely as possible to the probe
    and don't move it more to the full extent

    Press “Starts a new measure”

    Wait for the graph to stabilize and read the measured value

    If the value is still unsettled wait for further

    More is expected and more safe and accurate measurement is

    With background radiation or weakly radioactive objects you have to wait long
    (even hours if you want to measure differences in few nanoSievert)

    The radiation environment should be approximately 100 to 200 nanosievert

    When measuring on average or very radioactive samples can suffice even
    a few tens of seconds, wait until the lines stabilize.

    Normal measurements – of accuracy – from the lab
    Never use the analog meter, just need to search for minerals outdoors
    It's fast but not accurate, keep it locked.

    Always keep “Seconds FIR filter” to 9999

    Press “Starts a new measure” each variation of measurement conditions

    That ticks you are friends

  11. Livio says:

    Karl wrote:
    I have been trying all possible settings and can not get the program to react to my Geiger counter ....

    Livy wrote:
    Dear Karl, Please follow this Check List

    Using Geiger with a sound card
    Old joke that you are using a sound card input
    – connect the geiger to the Line-Input or Mic-Input
    – use a direct wire connection – not a microphone !

    Open the program Theremino_AudioIn
    – the VuMeter nust show the pulses (not at maximum an not too low)
    – eventually modify the “Windows recording mixer”
    – trim the trigger near to the pulses top but not over the top
    – trim the dead_time to about 1000 uS
    – set “Counter OUT” = “1”
    – set “Meter OUT” = “-1”

    Open the program Theremino_Geiger
    – set the language “English” using the menu “Language”
    – open the section “options”
    – set “InOut Slots” / “Input” = “1”
    – set “InOut Slots” / “Output” = “-1”

    Raise “Click volume” raise the Windows mixer

    The ThereminoGeiger must tick each incoming ray.

    Measuring with Theremino Geiger
    Choose the “sensor type” to suit your geiger tube
    Set “Seconds FIR filter” in 9999 (3 hours)
    Place the radioactive sample as close as possible to the probe and do not move more to the full extent
    Press “Start new measure”
    Wait for the graph to stabilize and read the measured value
    If the value is still unstable wait another time
    The more you wait, the more the measure is accurate and secure
    With the background radiation or very weakly radioactive objects you have to wait more
    (even hours if you want to measure differences of a few nanoSievert)
    The radiation environment must be approximately from 100 to 200 nanosievert
    When measuring average or very radioactive samples may suffice even
    a few tens of seconds for the lines to stabilize.

    For standard mesures – Precision – Laboratory
    Never use the analog meter, it is provided only to look for minerals outdoor, it is fast but not accurate, keep it closed.
    Keep “Seconds FIR filter” to 9999
    Press “Start new measure” after any changes in the mesurement conditions.


    • Livio says:

      Karl wrote:
      My geiger counter sends out a pulse of a certain “strenght”, which is always the same. So, as long as the volume is sufficiently high, there should be no problem seeing the pulses. In other words, there should be a wide volume range where the signal is easily seen, that is why I was so surprised that the volume settings should be so tricky.

      Livy wrote:
      Dear Karl, Have you seen the pulse after the audio card ADC aquisition ?
      Normally it is not so clean as you think.

      Use my scope to see pulses: DAA_V2.2

      Normally pulses are not “clean”, they can be saturated, noised ringed…
      so it is important to trim very very accurately the Theremino_AudioIn
      or you can:
      – count double pulses (dead time too short)
      – loose some pulse (dead time too long)
      – count double or count also the ringings (trim too low)
      – loose pulses or stop to work (trim too high)


  12. luca says:

    sono riuscito a fare funzionare l’invio dei dati tramite ftp
    la corretta sintasi nel mio caso e questa:
    nella riga ftp digitare
    così ho risolto il mio problema.
    naturalmente l’esempio sopracitato riguarda il mio caso , ma spero possa essere utile.

    • Livio says:

      Effettivamente e’ been difficult even for us to find the correct FTP syntax
      and is different from the one you have to use you.
      In our case (Server Aruba) the syntax that works is:
      with this incredible doubling of www theremino com !!!

      Therefore I would recommend to try all possible combinations and, in the most desperate cases, ask the provider.

  13. luciano says:

    Salve,I can not run the software can you help me?
    Start Theremino Bridge I select virtual com port 5 then connect
    Select probe type geiger smb20 boot
    I click Start a new measurement, I hear a sound for a split second and then nothing.
    the analog meter is fixed on 10.

    I state that with RAD and UPG works

    testing done with divcounter lcd arduino software Default_v8_r1_LCD_shield_w_button .
    signal picked up on pin 2 the jp6 through 100,000 pf capacitor sent to txd confertitore ttl-usb.

    It seems that the problem is Theremino Bridge and the virtual com port

    If I start geiger and geiger simulator works
    If I start just geiger doesn't work either with impulse sound card.

    • Livio says:

      I really have to get to Alexis, We have not released this software, as soon as I can I will’ help from him.

      However, something I know I:
      – the theremino bridge you send serial data
      – the data and’ a number from a 16 bit
      – at every tick of the tube the counter is incremented by one, and then the number does:
      0, 1, 2 ….. 65534, 65535, 0, 1, 2 etc…

      The theremino bridge and’ done to read the incoming data from the microcontroller Microchip of Alessio that counts ticks, not for a divcounter… Default_v8_r1_LCD_shield.. V8 etc…

      So I suppose you're putting serial information are completely different from those that ThereminoBridge expects, I'll put you in touch with Alex and perhaps together you will find a solution.

      In my opinion all solutions with Bridge or AudioIn, Although you can make them work well, are just a source of problems and unnecessarily complicated. The only solid solution, small and safe and’ a Master plus’ a GeigerAdapter. They do a 38 euros but and’ Another thing, the power supply and’ stabilized, minimum consumption, and you will never miss a tick.

      If you can explain what comes out of your serial vedro’ to help you better, Maybe I could modificarti the Bridge program, for now around the ball to Alex and see what he says.


      • luciano says:

        From the counter I have a ttl pulse ttl converter-usb and send via the virtual com software comes.
        I think the problem is ThereminoBridge wrong on my pc because I work all software com port input.

  14. Livio says:

    Theremino Bridge and’ made to read single pulses.
    And’ done to receive numbers already numbered and growing… 1, 2, 3, ….. up to 65535 and then again 1, 2, 3, … and so forever, If you don't send him this sequence (and it really seems to me that you don't) then Theremino Bridge may not work. We don't waste time and find another software that will work with your urges.

    In any case, software that is based on the single pulse count through a serial (that is very slow), will lose impulses whenever they come two neighbors, and it happens often!

    For this reason Alessio will count the pulses with a PIC that has a hardware counter able to get beyond the 50 MHz and only after they have been accumulated, sends the number already counted in serial….

    I don't doubt that everything will work ( more’ or less ) also via virtual com-, but the precision is lost from the start.

    If there was a viable solution I'd give myself a software adapter but I don't feel like losing days to then get an unreliable and too complex: USB –> Serial –> Virtual Com- –> Bridge –> Slots –> Theremino_Geiger

    Could you shorten it a little’ and improve performance in part by passing via audio using Theremino_SoundInput, even this would be a second-best solution but at least would only: Theremino_AudioInput –> Slots –> Theremino_Geiger

    If you want to try and do not know how to do it ask me tomorrow and I'll explain.

    Do you happen to have a fixed ? I don't spend anything to landlines.
    Because otherwise we're busy here…


    • luciano says:

      Thanks livio now I understand,It's a shame because the software has a nice graphics,and it is not excluded that orders the tabs to try them.
      you've been very kind.

      Hello to soon

  15. Livio says:

    I'm glad we understand each other, starting from this basis, maybe I can help you find a solution without spending anything for cards. Though, Since I have little time, would you help me back with a detailed list, with all components, connections and, possibly, what you know about signals, tensions and the initials of each component:

    – Geiger Tube (SBM-20)
    – Black with red 400 volts
    – Feeder (?)
    – Signal extraction (?)
    – SERIAL converter to (Arduino ? which sketch ?)
    – Serial type (RS485 ?)
    – USB Serial Adapter (a kind of pennetta ?)
    – Virtual serial, I guess
    – Operating system (XP, View, Windows7, Linux, Mac, 32 or 64 bit ?)

    I would also help a lot if I write next to each piece of the chain because you spent (indicative prices – approximated – and not the PC – only the pieces geiger/seriale / USB) this to realize how to help or advise future users who will find themselves in similar situations to yours. In this way the time used to get an adapter will be useful, in the future, to other.

    I know that it will take some time to do a detailed list but, for pleasure, make it right… think I'll lose ten times this time to give you a customized software.


  16. luciano says:

    That's all the info

    Geiger Tube (SBM-20)

    geiger scheme


    the signal is picked up by the leg 2 TO MCU (ENTRANCE TO ARDUINO) sent to txd of the converter usb-ttl.(QUICKRAD-UPG-RAD software work well)


    Geiger work I noticed that the log files is updated every second issue that doesn't get the signal in com Theremino via Bridge.

  17. Livio says:

    The whole final part about setting Theremino is fine, do not think of it again.

    Instead, unfortunately we are stuck before, I've written two important things:
    – What comes in from the serial’ ATMEGA on TX ???
    – how and’ the target price of the various components? (I need to understand the situation and can advise other users in the future)

    To understand what comes out on TX you can connect everything and then receive the data of Com5 with HyperTerminal or a similar program to receive serial. And then you should send me a piece of text that you receive.


    • luciano says:

      the signal is taken before the ATMEGA on tx is a ttl signal.
      HyperTerminal ?I wear at work.

  18. Livio says:

    Ok, I guess you're switching from Theremino_AudioInput careful to adjust well the trigger and put a dead time rather long otherwise you will double or triple counting pulses.

    I redid the Theremino_Bridge in DotNet and now begins to be a serious program, just finished putting it in place we'll publish.

    For now, download it from here:

    For pleasure, use it to see which data arrives from the serial, set the door 5, Awards “Show Log”, do you spend some’ of data and then copiameli into a message (both HEX ASCII) Or copy them into a TXT file and next day delivery to

    I remind you that I repeatedly asked the pleasure to write the costs of various parts, you're a pleasure to me to I do it to you. You write the approximate costs I finish software, you do not write I do not finish, AUG !


    • luciano says:

      the geiger of these tests is in kit , printed, components,LCD,atmega 328,(Arduino) 48 dollars
      with this no pc required.

      the TTL serial adapter (based on SILABS 2102 chip) 3 dollars

      the tests I've done to operate the software with your sound card or rs232
      working with hardware theremino

      probe sbm20 20 dollars
      stripboard lm358 endurance capacitors 4 Euro
      Matrix Board 741 endurance capacitors 5 Euro
      to power the spacecraft have used a module to power the lamps ccf putting in parallel at the exit two zenner 200v series.
      For details contact me on “”, I have patterns of all kinds. ;-)

  19. Livio says:

    Thank you !
    You gave me a great idea of what to buy and how much you spend ( about 80 dollars )
    Now if I log of what you get from the serial you finish Theremino_Bridge.


  20. Livio says:

    Fabio wrote me that in a couple of minutes spanned 60nS/h and asks me what are the typical values that you have to wait in the first tests with Theremino_Geiger. I reply here on the Blog for the sake of all who were in his situation.

    The Fund
    Two minutes to measure the Fund are still very few, continues for at least half an hour and then let me know how you measure.

    In the Turin area on bottom should be around 0.09 us/h (We normally say 90 NS/h)

    Search samples
    Since we don't have samples to measure you can use the time to impratichimento to search for radioactive samples at home…

    First you have to measure the bottom (at least one hour – and after you shouldn't move the probe)

    Then you start with things that are glazed ceramic, better if gloss, better if red or orange (dishes, pots coffee cups, coasters, tiles, etc…)

    The sample locations as close as possible to the center of the tube, Awards “Start” and wait for a long time, If anything has stabilized a bit’ higher up the line in the bottom then it's radioactive.
    (subtract the bottom and we write over – for example, – 50 NS/h net)

    If you don't find anything radioactive go buy a jar of dietary salt “NovoSal” or “Gemma”, NE ways a 50 grams in a teaspoon of PVC and lean over pipe – This will score 200 NS/h

    Then go find pieces of pumice stone (real natural pumice stone, not fake) and this will score 100 NS/h plus’ of the Fund.

    Good luck.

    Miscellaneous information
    Open the menu “Help” / “Environmental radiation” and you'll find a helpful table that can give you a
    idea of what to expect as background.

    On the site You can find other useful information

    especially on pages:


    • Fabio says:

      Tried … actually, These are the raw data '’ ( = taken without paying too much attention to the times )
      1) in about 40 min ' background noise’ proved to be of 70 NS/h
      2) at this point I put next to the SMB pipe-20 a piece of pumice (size = approx. 3 cm in diameter and I started a new reading (correct operation ?) … well, After about 40 min. the reading amounted to 115 NS/h

      Well, It seems to me that all this confirms what I wrote above Livy !

      • Livio says:

        I'd say you're very close to an accurate measure! And you also measured the pumice which is definitely the most difficult to measure, try the salt and you will see how marks!

        Your surgery “started a new reading (correct operation ?) ” is exact, do you have to be like’ each new measure (Maybe just even less than 40 minutes)

        I would recommend though to refine it a little’ the calibration because both the 70 NS/h that 115 NS/h seem slightly scarce then your pipe should be good enough and have few pulses of background – stoop the BKG tube until the bottom marks around 90 NS/h.

        At this point you should be around +/-10% from actual, that is already a lot in this field. You should also consider that we are using incorrect Geiger tubes for the energy, You can then mark also 3 times longer at low energies, around the 50 Kev, that the energies around the 500KeV. There are also geometric considerations (sample size and dimension of the active area of the tube) that, combined with the distance-tube champion, further complicate the measures. Finally there’ the effect of beta rays, passing the thin walls of SBM20, and that may increase the sizes of 5 or 10 times in some cases.

        Ultimately reaching measures for type: According to the same distance, with the same geiger tube, This sample mi scored twice as that is the maximum that can be done without specifying so “impossible” measuring conditions.

        Welcome to radioattivomani

  21. luciano says:

    I saw the post now.
    in count…….

  22. luciano says:

    then in 1 and half the average is
    CPM 60
    us/h 49
    values read from the local display.
    I'll let measurements + precise in the coming days ,I am in the process of adjustment to a new tab,and given the current time and arriving from the North …….

  23. luciano says:

    Acer laptop.
    This is the log done with RAD probe mail smb20 mail outside.
    windy weather storm.
    many lightning.
    the castelli romani area north of Velletri in km3 500mt slm.

    02/12/2012 18:54:17 , 47
    02/12/2012 18:55:17 , 62
    02/12/2012 18:56:18 , 57
    02/12/2012 18:57:18 , 68
    02/12/2012 19:49:47 , 51
    02/12/2012 19:50:48 , 48
    02/12/2012 19:51:48 , 60
    02/12/2012 19:52:48 , 63

    • Livio says:

      Changes in this log are not due to environmental changes.
      To stabilize the measured values you must integrate for a very long time, a given every minute up and down randomly, It just shows that the impulses received from the Geiger tube are few and random.

      I don't know if the RAD has time to selectable integration, in such a case to measure the bottom I would recommend you time not less than 30 minutes.

      Hello, and good experiments

  24. luciano says:

    even the most professional geiger has rhythms “random” No geiger gives the rhythm from ….metronome…
    If I do the test with readings every 30 minute values will always be 40 to 70 CPM never always a constant value .
    otherwise, just a counting pulse for an hour then you divide x 60…..
    I tried ,closing the probe into a metal container in this case I found a strong attenuation of readings (shield this beta )then the probes work fine does not distort the readings.
    I also tried it on tour to three different more one military, in which case each said his….

    the important thing that interested me which software theremino read the impetus comes from the probe accurately.
    then we're not harp ;-) When we begin to feel nervous tic tic so better take off….that measure.

    • Livio says:

      The geiger that define “Professional” are made to respond quickly (This need to get away) and also "random" rhythms, as you say, because they use very short integration times (often less than two minutes) in order to respond quickly.

      We seek instead of making measurements “from the lab” and in this the Theremino_Geiger can't be beat.

      By running a “integration” for a long time (with FIR filter – Finite Impulse Response) then the measures do not suffer more than this randomness and become inferior to 1% accurate even with errors (that in this field are minimal errors)

      The program automatically does this thing ThereminoGeiger, so you don't have to divide… , you just have to use it the right way, depending on the type of measure:

      (SO 1) Set 9999 seconds to FIR filter – Press “Start” each new measurement and wait until the number has stabilised and the error falls below the minimum 5%

      (SO 2) Set 60 seconds and measure as all geiger “normal” – I mean’ with constantly changing values of 90% In addition and in less. This way – very inaccurate – It has the advantage to respond quickly to changes and can be used to look for radioactive minerals going around with a tablet or a net-book.

      (SO 3) Use the analog instrument should have which is even more inaccurate but even quicker to respond so great to look for radioactive minerals going around with a tablet or a net-book.


      What you say to the fact that the important thing is to get a rough idea and its situation is very right !


  25. luciano says:

    where are we with Theremino_Bridge?
    must get new hardware by Theremino_geiger ?
    because I want to order it.

  26. luciano says:

    All zeros if I approach a sample radioatttivo out some 63.

    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 63 …….. omissis …….. 00 00 00 00 00

    • Livio says:

      But let me get this straight….
      the speed with which the zero or 63 depends on radioactivity ?


      – without standard with only bottom comes a number (0 or 63) every five
      seconds or so ?

      – with radioactive enough sample get many numbers (0 or 63 that
      are) per second ?

      So what:

      – without the log fills very slowly ?

      – with the sample log fills in seconds ?

      Behave like this ?

  27. Livio says:

    I made a version in the dark 1.4 He has a strong chance of work !

    Download it from here: http:/
    …try it and let me know if it works.

    1) Hold down the check-box that says “Rad protocol”
    2) Be careful of the slot (What time and’ zero and must be the same as the geiger)
    3) Try with different baud rates


  28. luciano says:

    pretty much zero everything out and very slowly when I approach the radioactive sample(mantle) increases the speed of the zero and in addition they come out even 63.

  29. luciano says:

    The version 1.4 work that is now Theremino_geiger finally reads the InPulse inviat0 the com port.
    1.4 Theremino_Bridge_V always displays all zeros no more 63 :-))
    Some might be interested to know what goes on the com port…….

    Adesso lyrics with a nice Fallout

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