testo 425 is a compact anamometer with a fixed thermal flow velocity probe. The probe head has a diameter of 7.5 mm. With the extendable telescope (length max. 820 mm), the measuring instrument is suitable for flow velocity measurement in ducts. The testo 425 also measures
extremely accurately in the low flow velocity range. The volume flow is directly shown in the display. For the purposes of volume flow calculation, the duct area can be easily entered into the testo 425. In addition to this, the instrument can be switched over to display the current
temperature. Timed and point mean value calculation provide information on the average volume flow, flow velocity and temperature measurement value. The Hold function allows the current measurement value to be frozen in the display, min./max. values are also displayed at the press of a button.