PGAS-CO2 & O2 Gas Monitor for Greenhouse 1. Can measure the concentration of CO2 and O2 in greenhouse 2. Alarm Brief introductionPGas ... -24 Portable 2 in 1 Gas Detector, can continuously measure ... the concentrations of any two kinds of gas continuously in buildings, offices, laboratories, greenhouse, greenhouses & etc. 1) Jack of probe2 ...