Pyroelectric sensors for detecting CO2

[leper]

Hi all! I was reading through thread250-71127 on a similar topic, and I'm hoping to make a CO2 level detector with an IR source and a pyroelectric detector. Does anyone know of a supplier in Australia that sells these detectors with a 4.25u band pass filter built in?

If I were to get one without a band pass filter, would it be possible to make a band pass of my own with readily available materials?

Cheers!

 

[leper]

I managed to acquire a thermopile today which should do the job, now I just need a filter to put in front of it which only allows ~4.25u through... any suggestions on where I could find such a thing?