NevadaNano’s Molecular Property Spectrometer™ (MPS™) MPS Refrigerant Gas Sensor provide accurate and reliable detection of mildly flammable (A2L) R-32, R-454b blends, R-1234yf and other low global warming refrigerant gases such as  (A1) R744 as well as (A3) R290 and R600 common in HVAC applications. With a 15+ year calibration interval and lifetime, the MPS A2L Refrigerant Sensors deliver industry-leading performance and the lowest total cost of ownership.