8 measurement units to choose from: psi, kPa, hPa, Pa, mm H2O, mmHg, inch H2O, inch Hg2 air flow units to select from: m/s, fpmIntegrated density compensationBacklit display, min/max values, hold functionThe testo 512 differential pressure meter is available as four different models. This model has a measuring range from 02 hPa and is ideal for measuring pressure differences at filters and for carrying out pitot static tube measurements in air ducts at air flow speeds between 2 and 17,5 m/s.