CO2 sensor recommendation

Been a while since we posted here, as someone noted all NDIR CO2 sensors drift, it is how it is controlled that differentiates manufacturers. At Amphenol we have two types (the only company to have two), one uses Automatic Background calibration, the other has a second internal reference (dual beam or dual wavelength). Read here for more information on which is best for your application.

Farnell and others list our modules. T6613 and T6713 are ABC variants, T6615 is a dual channel.

VOC sensors only offer an equivalent CO2 value, we know because we list one too, the MicS VZ89TE. Ultimately the only real way to monitor CO2 commercially is with NDIR at the moment.

Power is an issue, as the most reliable economic source of IR for sensors remains an incandescent lamp, and they consume pwer, we are doing a lot of work at the moment on reducing consumption. But essentially the common way of reducing it is to measure less frequently, so the downside is reduced response time, which may or may not be an issue. It can also effect any self calibration routine. It should also be noted that in general the sensor modules cannot be turned on and off, as they require a settling time to reach thermal equilibrium.

We also have put up some code to interface to our sensors on github for the Arduino, it is written in C++.

Thank you very much for an additional insight. I noticed there is a RoadTest with T6713-6H CO2 Sensor Module, so I am looking forward to seeing the results. (I didn't apply, because I am just an amateur.)

It took me a few weeks to gather the previously written information and I came to the same conclusion - NDIR is the only usable CO2 measurement technology. By the way, I also found out that Amphenol sensors feature I2C, where CozIR LP from Gas Sensing Solutions only has MODBUS over UART (one more point for Amphenol).

I already got a CCS811 VOC sensor mentioned above and I am afraid it is unusable even in home environment.

Actually the GSS Cozir isn't MODBUS but a simple human friendly protocol so you can easily drive it from Hyperterminal or similar as well as from a micro. This makes it easy to debug systems that use it.

The main difference is power and speed:

Coziir, 3mW average power, 1.2s to first reading no warm up

T6615, 165mW average, 600s to first reading,

This is because the Cozir uses solid state IR LEDs and photodiodes made by GSS in Scotland !

(I must acknowledge an interest here - I do consultancy work for GSS.)

MK

Note for your (and others) clarifiication, our T6713-6HT6713-6H is a T6713 part with a 6 way header on it.

Regards,

Note for your (and others) clarifiication, our T6713-6HT6713-6H is a T6713 part with a 6 way header on it.

Regards,