Here’s a cleaner example with humans. Just a warm up and cool down. CO2 should not have changed.

A response to this would be appreciated. This is a serious issue that calls in to question the accuracy of all uRAD products.

Wolferl, that is not acceptable. Our Gaslab 501, IQ Air Visual Pro ($239) and AWAIR Element ($149) all provide accurate CO2 readings that are in agreement with each other and that properly compensate for temp changes. Your readings are off by multiple 100’s of PPM, not just 50 or 5%. Your device costs 2x to 4x more than these others, it should be better, not worse.

“…one never knows” – YOU should know. You are the manufacturer.

“that sensor performs some magic self calibration”. Some magic? You are the manufacturer of a device that you are selling. You should fully understand exactly what your vendors are doing. Others who use this same sensor are getting accurate results from it, why are you not?

Apologies @Wolferl. You are listed as Mod and I assumed that you work for Radu.

“If you are not happy with its performance, talk to Radu.” – Exactly why I posted in the support forum that he normally frequents. This is beyond my individual happiness with this device as it calls in to question the accuracy of every device made by uRAD.

Thanks Radu. RMA completed.

My understanding of dual beam sensors is that they calibrate each other. Calibration doesn’t seem to be the problem here but rather a missing calculation for CO2 as a function of temp?

Thanks Radu. Neither of those s/b contributors.

– Humidity in a sauna is low, typically between 5-50% RH. Given that humidity in a sauna is produced by ladling water on the stove rocks I’m not sure it’d even be possible to get it higher. I think they are confusing Sauna with a Turkish Bath or Steam Room.

– The A3 was placed low in the sauna where the temps never get above 60°c and rarely (or never) even above 50°c.

You can also see this in the temp and humidity of the image I posted above. Both are within the parameters of the sensor and more so within the parameters of the A3 that states ‘-20°c to +65°c’ (and which should likely be changed if the sensors have tighter parameters).

As I pointed out in my original post there appear to be two problems of the A3 providing quite erroneous data:

1) ALL CO2 readings are high. Even outside where the USEPA and my own devices are all giving readings of 390-425, the A3 is indicating over 600.

2) It is not correcting for temperature as every CO2 measurement device must do. Compare the CO2 and temp lines in the two images I posted. Whether this is supposed to be done by the sensor or in the A3 code it is not being done and my guess is that this affects every A3 device with this same sensor and possibly every A3.

Thank you,