Help?!?! Cant figure out how to calibrate older PPM 3 CO2 controller

[iscrog4food]

I have an old PPM 3 co2 controller which has come out of calibration. After searching online I found the instructions which say to hold enter and clear for 5 sec until "Air cal" appears and it "Nitrogen Cal" Appears press mode one more time until "Air Cal appears". When I follow these instructions the display reads "ALtitude 5000" and there is no option for "Air Cal". I also tried to find contact info for CAP and I surprisingly couldn't find anything. Can anyone help?!

 

[SuperCan]

Do you know anyone who has a meter that is calibrated if you do you can just see how far yours is off and record the offset until you figure this out.

 

[iscrog4food]

I have one that is in calibration but I am not sure it works like that (if it is 200 ppm off I don't think that means 200 ppm across the whole range.)

 

[SuperCan]

You can test it by changing the concentrations or probably even by looking inside and outside. I know basically how the meters work (I believe it is infrared spec) but I do not know how the equations work. Usually I think that it should work this way I know that it would in a UV-spectrophotometer which uses some of the same principles because we used these to do protein assays in my old lab.

 

[woodsmaneh]

Contact R & M supply 866-476-9768

http://www.randmsupply.com/

 

[iscrog4food]

ok will do thanks woods