WHAT IS THE MAXIMUM CARBON MONOXIDE CONCENTRATION THAT I CAN MEASURE?
This depends on how long the measurement period is. The longer the required measurement period the lower the maximum CO concentration will have to be. Required accuracy is also a factor, since the sensor will begin to drift with time as it becomes saturated. The diffusion opening of the sensor is the governing feature that determines maximum permissible concentration. The smaller the opening the higher the allowable maximum concentration. Unfortunately there is a practical lower limit for the opening, before other factors begin to affect sensor performance. Typically, for the lowest practical diffusion opening (and not using dilution of gas methods) and reasonable accuracy (10%), 40,000 PPM for 10 minutes or 20,000 PPM for 20 minutes are possible. (Such a sensor will not operate with sufficient accuracy below 1000 PPM).
