Help Needed identifying a component

[zorax]

Not sure if this is the right section to ask this, but here it goes:

My friends and I are working on a project for Uni, and we took apart a Safety Siren Pro Series HS71512 3 Radon Gas Detector to study the components inside it.

We have managed to identify all the components apart from one. This was in the main detection chamber of the device - we believe it to be some sort of Scintillation Cell, but cannot be sure.

Pictures have been attached of the component in question - it's the small shiny black square thing, on top of the large green square. The whole thing is stored in the black plastic box, that we believe to be the ionisation chamber.

Our theory is that the radon particles ionise the air the chamber, and the ions are detected by this black square somehow. We just aren't sure what this square is, or how it detect ionised air particles (if it does at all).

Would really appreciate it if someone could identify what it is and let us know. Thanks

 

[BradtheRad]

Scintillation Cell is as good a guess as any. It looks unusual enough to be a special component.

Try doing a search for scintillator repair, or do-it-yourself projects. If they use a similar component then your guess will be confirmed.

Do you have a source of radioactive emissions? Some geiger counters have one attached to the housing. It's a way to test operation. The scintillation cell may or may not be easily overloaded, however. A scintillator is very sensitive.

 

[keith1200rs]

It could simply be a photodiode. Masked photodiodes are used for radiation measurement.

Keith

 

[Fragrance]

It could simply be a photodiode. Masked photodiodes are used for radiation measurement.

Keith

yes you are right mask photo diode can used for radiation measurement, elektor publish a artical couple month back on photo diode as short band to long band radiation measurement.
but poster stated that it is GAS measurement instrument not radiation measurement further from the picture it look like hospital central air and GAS supply monitoring system

regards
Fragrance

 

[udhay_cit]

Please look closer. The black sensor mounted at center. A red led also placed near. both of it covered with a black plastic box[so surly the LED not for indication purpose]. This setup can be used to sense the gas [particularly smoke]. But the LED should emitting a know wavelength. The sensor may be a photo sensor attached with pyro optical filter, so the filter will allow only one wave length [may be LED'S wavelength]... Its my guess....

I need to know only one thing Is there any ventilation hole available for gas flow to the black plastic box? I can not see this through your photograph...:-D
I did some project with this concept... That's why....:wink:

Regards
Udhay

 

[keith1200rs]

As it is for measuring Radon gas, I assume that it does that by measuring the radiation given off by the Radon, in which case a photodiode is a possibility. There are plenty of papers on using PIN photodiodes for the measurement of Radon.

Keith

 

[zorax]

We found something online that indicated it was a photo-voltaic sensor after all:

"It is a solid state continuous radon monitor which utilizes patented technology. At the heart of the device is a measurement circuit and pulse processing software which records alpha events on a photovoltaic sensor. Radon daughters create a spark when they come in contact with the potential across the collection dome and the photovoltaic sensor counts these pulses. The software equates pulse volume into pCi/L (Pico Curies per Liter) and then displays the information on the LED display"

https://testproducts.com/alarm-radon-detector-monitor-hs71512-approved-series-p-701.html

So I guess that's what it is.
Thanks for your help guys

- - - Updated - - -

We found something online that indicated it was a photo-voltaic sensor after all:

"It is a solid state continuous radon monitor which utilizes patented technology. At the heart of the device is a measurement circuit and pulse processing software which records alpha events on a photovoltaic sensor. Radon daughters create a spark when they come in contact with the potential across the collection dome and the photovoltaic sensor counts these pulses. The software equates pulse volume into pCi/L (Pico Curies per Liter) and then displays the information on the LED display"

http://testproducts.com/alarm-radon-detector-monitor-hs71512-approved-series-p-701.html

So I guess that's what it is.
Thanks for your help guys