Hi, I have to measure an avalanche photodiode in normal mode (non-geiger mode).
I'm using First Sensor AD500-8 datasheet
The photodiode will be working below breakdown voltage.
The problem is, how can I measure microamps with arduino? I know I can`t just connect it to the board.
Don't waste your time with Arduino. Use a meter capable of measuring microamps, or the uCurrent and a DVM
jremington:
Don't waste your time with Arduino. Use a meter capable of measuring microamps, or the uCurrent and a DVM
I have seen uCurrent before, but I don't know if it will be able to measure nanoamps at that voltage (aprox 80V).
Current can be measured anywhere in the circuit. Choose an insertion point that is close to ground reference, not 80V.
Post a circuit diagram for how you intend to set up the photodiode.
jremington:
Post a circuit diagram for how you intend to set up the photodiode.
Schematic attached.
Edit: I found this: http://www.linear.com/solutions/5426
Can I use an opamp? will it resist 200v at input?
will it resist 200v at input?
No.
The avalanche photodiode will drop ALL the voltage, unless you destroy it by exposing it to too much light while powered up, or exceed the avalanche voltage without using a current limiting resistor.
The avalanche photodiode is rated for 0.25 mA absolute maximum. Where is the current limiting resistor in your circuit?
jremington:
No.The avalanche photodiode will drop ALL the voltage, unless you destroy it by exposing it to too much light while powered up, or exceed the avalanche voltage without using a current limiting resistor.
The avalanche photodiode is rated for 0.25 mA absolute maximum. Where is the current limiting resistor in your circuit?
I thought I would not need it, because I will use the diode for ultra low light detection.
Is uCurrent the only solution to convert those nanoamps to voltage for arduino?
I take it you have not bothered to research how one uses a photodiode - of any sort.
Start here.
jremington:
I take it you have not bothered to research how one uses a photodiode - of any sort.Start here.
Dude, you have no idea of how many hours of research I have spent on these diodes. The thing is that I don't want to mess with "high" voltage and arduino before I'm absolutely sure that the board won't burn.
Anyway, I didn't found that ppt, thank you, I will take a look. Btw, the diode is going to be used to detect light from a scintillator, that's why I want to make sure it will detect such low light with the smaller noise possible.
PS: Please do not think that I wrote this post asking for information because I didn't bother to find it for myself.
I said I wanted to measure a scintillator, not that I wanted to count photons.