The testo 512 0 2000 hpa for simultaneous pressure and flow measurement it has two switchable units for current ms and fpm for pressure eight units are adjustable kpa hpa pa mmh2o mmhg psi inh2o und inhg the damping is adjustable for sliding purposes the density compensation is integrated the displayed actual value with the hold button can be held in the display the min max value can be displayed and stored in the device