Testo 512 shows pressure and flow velocity simultaneously in an easy to read large backlit display measurement data is printed on site with date and time as well as minimum and maximum values testo 512 has two switchable units for flow ms and fpm eight units can be set for pressure kpa hpa pa mmh2o mmhg psi inch h2o inch hg adjustable damping for sliding mean calculation density compensation is built in the displayed actual value can be frozen in the display by pressing the hol