Freeware Detector Program, Digital Geiger Counter

[Brian_Gage]

Please excuse the newbie intrusion if this isn't exactly the correct place for this matter. I recently downloaded a program called "Digital Gieger Counter" from Instructables, but it has zip for instructions. I can't appreciate the graphics or graphing functions, but it does allow me to switch from American to International (mSv) and records counts in seconds. Has anybody ever looked at this program? Can anybody tell me what numbers are saved in the two columns when "save as" is used?

I'm trying out different counting programs with my Monitor 4EC to sort out deviations in readings. So far, using thorium ash in a baggie as my source, different programs give a similar spread of increased CPM as I switch the attenuation higher. For example, 850 cpm @ X1, 1000 @ X10 and 1200 CPM @ X100. This spread gets a lot worse with an americium button. X1=8500 CPM, X10=19,000 CPM and X100=40,000 CPM. When listening to the data/earphone port with an earphone, there is a distinct shift to a higher pitch or tone with the higher attenuation settings. SE International hasn't given me a satisfactory answer. I'm thinking the X1 lets pulses pile up at higher count rates, giving a false (lower) reading with the counting software.

Though programs like Digital Geiger Counter, Geiger Graph and Rad 3.from Black Cat 0 use graphics and graphing displays, they still work with my screen reader, allowing me to 'see' into count boxes and save count records for import into notepad or Excell.

Of course, any feedback will be appreciated. B. Gage

[ShowerScience]

I am a newbie also and note you did not mention PRA (Pulse Recorder Analyser) in your software list. Yes it can be used to log pulses from a variety of devices and may even help you resolve the other questions you mention with respect to the higher tone and pitch.

The other related software is InTune which is also a free software designed to work with PRA. Hope this helps.

http://www.physics.usyd.edu.au/~marek/pra/index.html
http://www.physics.usyd.edu.au/~marek/intune/index.html

[ShowerScience]

Sorry to reply in two parts. It is also worth considering the distance of the radioactive source from the detector. In my newbie experience so far, there are limits to the number of counts any apparatus can measure with respect to time. The "pile up" you mention may be indicating the limit of your PC laptop/other to process the counts/pulses. If the pulses are being processed by a sound card, then the limit is defined by the maximum sampling rate of the sound card in the PC and not the processor Intel, AMD, Celeron, or other.
One solution then is to move the radioactive source further away from the detector at a set distance and then obtain comparative measurements from other sources at the same set distance. This would reduce the load on the processing power and should obtain more accurate results at the expense of lower counts.

[Brian_Gage]

Hi and thanks for the response. Yes, I've also gotten and tried PRA 4.0, and had the same problem, plus a couple more. PRA worked after fiddling with the line-in levels, and PRA also gave me quite a spread in CPM between X1 and X100 attenuation. About 200 CPM on each setting as I recall. Doug Coulter suggested I might try an RC filter on the line-in to shave off some of the noise. The problem I have with InTune is that I'm totally blind, and selecting a segment of waveform is beyond my capability without a sighted assistant. That would certainly solve any noise or false pulse readings.
I think that the Monitor 4EC, being a fairly basic radiation survey meter, allows real high count pulses to pile up somewhere in the data port hardware, at least at fairly high readings., So, the Geiger Graph and PRA both see one pulse where there might be two or three. On the higher attenuation settings, with the sharper pulse tone, this problem goes away ... or, I may have it completely backwards. Thing is, at 2k CPM to 40k CPM, there's this spread. I don't know which setting to believe, the X1, the X10 or the X100.

My original question was if anybody had downloaded and tried out the Digital Geiger Counter program. The screen display and settings options aren't all that friendly with a screen reader. I finally got it to show changing count rates with a thorium ash sample, and it did record some numbers, but the two columns of numbers made no sense and there's no documentation. You gets what you pays for.
Brian.

[Steven Sesselmann]

Brian,

In PRA version 4.0 it is no longer necessary to hand pick the pulses using Intune. There is a new function called Pulse Shape Acquisition, which does it automatically, you simply set the LLD so that it does not acquire a pulse shape from the noise.

Regarding the RC filter, you want to achieve a time constant (K) in order of..

K = R * C = 1/(pi * 48000) = 6.6 x 10^-6

If C = 10 nf, R = 660 ohm

Steven

http://www.beeresearch.com.au

[Brian_Gage]

Yesterday I was reviewing test data I'd collected on the Monitor 4. I'd forgotten about some data using PRA 4 and an alpha button. The averages for 10 minute runs were as follows:

X1=52216.5 X10=53439.5 X100=53252

This PRA run was the first that showed the count numbers all close. Perhaps having the X100 count lower than the X10 threw me, or more likely it was real late and I was nodding off and forgot I'd saved this data.

This was with the line-in audio for Sound Max integrated set at 48k and mono, in Windows XP. Maybe the problem is with the serial input and Geiger Graph software and not the Monitor 4?
Brian

[Brian_Gage]

PRA 4.0 is a simple, effective program. Marek even modified the current version so that it would work better with my JAWS screen reader. The program works as a simple pulse counter and the trigger threshold can be set from 0 to 100 to elliminate noise and just catch the pulse peaks from an audio feed. At present my setting is 75. I've connected my Monitor 4EC via a stereo cable to the line-in and adjusted the audio level to 60%. Didn't need any RC filter or impedance match either. You can also set the length of time the program will count, and the count interval in seconds.
This program can also be used with a scintillation probe and preamp setup to perform gamma spectrum analysis. Check out a post somewhere here by Carl Willis.

Hey, it's free and worth lots.

Brian