Santacary FH20 Pocket Formaldehyde (Oxymethylene) Meter Monitor Detector HCHO Monitor Temperature Humidity Moisture Meter with Alarm for office home gardening furniture wooden floor mattress Santacary FH20 is a precise formaldehyde monitor for detecting low level concentrations (0.01 mg/m3) of hazardous formaldehyde vapors in houses, offices, classroomes, or cars. FH20 is calibrated by OWLSTONE OVG-4 Formaldehyde Calibration GAS Generator. There is also automatic temperature compensation in formaldehyde measurement. Exposing in 3.0mg/m3 of formaldehyde concentration will cause biting sensation in eyes and nose. FH20 did not measure such outrageous results in general environment (when in stable reading). It is the only product in the market that has trend function to show the formaldehyde change in more than 24 hours. FH20 can measure the ambient temperature with selectable C or F and the relative humidity.