Seeed grove physical sensor modules seeed studio 101020045 the grove carbon monoxide sensor from seeed studio can measure carbon monoxide in concentrations from 10 to 1000ppm its output is a single analogue voltage which can be read by any microcontroller with a spare adc input and matching supply voltage the manufacturers datasheet available online has a conversion chart for determining gas concentration given the sensors reading please note that the best preheat time for the sensor