Handheld Digital ManometersPrecision instruments test air or gas pressure in HVAC systems, laboratory testing, field calibration, and medical respiratory support equipment. Batteries included. Extech PS100 SeriesDisplay readings in 11 selectable units with high resolution on backlit LCDgreat for field, manufacturing, cleanroom, HVAC/R, and laboratory/R&D use. Zero function allows offset correction or measurement. Manually store up to 99 readings with max./min. values and relative time stamp. Feature Hold, Auto-Off with disable, large backlit LCD, and PC interface (cable and software sold separately).