I have an air-jacketed CO2 incubator and I need to calibrate its thermal conductivity CO2 sensor. However, I do not have a CO2 sensor that is independent of the incubator to measure the CO2 levels. Is there a method to calibrate the T/C CO2 sensor without having an independent instrument to verify its calibration?
Hi Ashlee
place your RPMI which should be 7.2-7.4 at 37 degree C into the incubator in a 24 or 6 well plate.
Take some phenol red containing HBSS, prepare aliquots and adjust pH with pH meter and NaOH, HCL to 6.0 up to 8.0 in the intervals you require for your precision (e.g. in the outer wells of a 24 well plate or in a 6 well plate as above)
Take the equilibrated RPMI out of the incubator and compare the color. It is easier with a white sheet underneath and the same level of liquid above and the same phenol red concentration. This is probably the cheapest way but will take time. It takes ca 15-20min for 0.5cm liquid layer to equilibrate in an incubator when it stands still.
Best
Heiko
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