It features a new generation of CARBOCAP sensors with Microglow technology. Microglow is a Vaisala-patented silicon MEMS emitter infrared source that  is built in-house at Vaisala.

Low power consumption enables correct RH+T measurements in CO2 instruments. Replacing the incandescent light bulb has improved stability. Moreover, the sensor’s operational life has been extended by 50%. Through simplified design and intelligent optical design fewer components are required, which help to increase overall reliability. The GMW90 includes a sliding cover, which allows for faster calibration/service. The company says compliance and traceability of measurements are never compromised.