The testo 521-3 differential pressure measuring instrument is designed for high-precision differential pressure measurements in air conditioning and ventilation technology. It can be used, for example, for measurements in clean rooms and for flue inspections – thanks to a high level of accuracy and outstanding resolution. In conjunction with a Pitot tube (optional), the integrated pressure sensor measures flow velocities of +1 to +20 ms.
The integrated temperature-compensated differential pressure sensor performs measurements to an accuracy of up to ± 0.5 Pa. In addition, you can attach up to 2 further optional probes to the measuring instrument. This means you can flexibly adapt the differential pressure measuring instrument to your application. You have the choice of the following probes:
Differential pressure probes
Absolute pressure probes
Relative pressure probes
Temperature probes (e.g. surface probes or immersion and penetration probes)

The testo 521-3 differential pressure measuring instrument is designed for high-precision differential pressure measurements in air conditioning and ventilation technology. It can be used, for example, for measurements in clean rooms and for flue inspections – thanks to a high level of accuracy and outstanding resolution. In conjunction with a Pitot tube (optional), the integrated pressure sensor measures flow velocities of +1 to +20 ms.
The integrated temperature-compensated differential pressure sensor performs measurements to an accuracy of up to ± 0.5 Pa. In addition, you can attach up to 2 further optional probes to the measuring instrument. This means you can flexibly adapt the differential pressure measuring instrument to your application. You have the choice of the following probes:
Differential pressure probes
Absolute pressure probes
Relative pressure probes
Temperature probes (e.g. surface probes or immersion and penetration probes)