Hi, can someone help me understand how this circuit works, I know what transistor, collectors, and resistors are, but what are their function in this circuit, and how does it work part by part? And how accurate is it? I am doing project on this, to find out if skin perspiration changes when one lies. How accurate is it (at measuring perspiration, not at detecting lies)? And also, what type of meter should I use (ohm meter, volt meter, amp meter, or etc)?

http://www.aaroncake.net/circuits/lie.asp

Thank You!

 

This must be the third time around. Try some links -

http://instruct1.cit.cornell.edu/courses/ee476/FinalProjects/s2006/hmm32_pjw32/index.html

http://www.extremenxt.com/gsr.htm

It's an imprecise measurement at best.

 

This must be the third time around. Try some links -
http://instruct1.cit.cornell.edu/courses/ee476/FinalProjects/s2006/hmm32_pjw32/index.html

http://www.extremenxt.com/gsr.htm.

That's true lol, but they are all a little different (questions), but there is no really circuit shown in those websites.

It's an imprecise measurement at best.

Why is it imprecise? And how does the circuit work?

Thank You!!!!

 

That circuit uses skin conduction to partially turn on the transistor. It will work very differently on a hot day than a cold one.

Did you read the articles?

 

That circuit uses skin conduction to partially turn on the transistor.

I still don't understand exactly how everything works. How? And why isn't it accurate?

It will work very differently on a hot day than a cold one.

Why?

Did you read the articles?

Yes, the first one is kind of confusing, where is the circuit? There are two shown there. And the second one says that he wrote a simple data logging program that records the RAW sensor value every 10 seconds into a file, but doesn't give us the code.

Thank You!!!!