Differential pressure measuring instrument testo 521-3 (up to 2.5 hPa)

The testo 521-3 differential pressure measuring instrument is designed for high-precision differential pressure measurement in the air conditioning and ventilation industry. Thanks to its high precision and outstanding resolution, it can be used for measurements in cleanrooms and chimney inspections. Together with the Pitot tube (optional), the integrated pressure sensor of the testo 512-3 can measure flow velocities from +1 to +20 m/s.

The integrated temperature-compensated differential pressure sensor performs measurements with an accuracy of up to ± 0.5 Pa. In addition, you can attach up to 2 optional probes to the measuring device:

Provide cover: Differential pressure meter testo 521-3, batteries and test paper from factory

Features of the testo 521-3 differential pressure meter

Technical specifications of testo 521-3

Temperature – NTC
Measuring range	-40 to +150 °C
Accuracy	±0.2 °C (-10 to +50 °C)* ±0.4 °C (Remaining range)*
Resolution	0.1°C

Temperature – NTC

Measuring range

-40 to +150 °C

Accuracy

±0.2 °C (-10 to +50 °C)*

±0.4 °C (Remaining range)*

Resolution

0.1°C

*Accuracy information applies only when the device does not have a measuring head connected.

Temperature – TC Type K (NiCr-Ni)
Measuring range	-200 to +1370 °C
Accuracy	±0.4 °C (-100 to +200 °C)* ±1 °C (rest of range)*
Resolution	0.1°C

Temperature – TC Type K (NiCr-Ni)

Measuring range

-200 to +1370 °C

Accuracy

±0.4 °C (-100 to +200 °C)*

±1 °C (rest of range)*

Resolution

0.1°C

*Accuracy information applies only when the device does not have a measuring head connected.

Differential pressure (internal sensor) – Piezoresistive
Measuring range	0 to 2.5 hPa**
Accuracy	±0.5 Pa (0 to 20 Pa) ±(0.5 Pa ±0.5 % measured value) (20.1 to 250 Pa)
Accuracy	0.1 Pa
Static pressure	1000 hPa
Overload	50hPa
Zeroing	up to 0.5 hPa

**Sensor is not suitable for long-term measurements

Differential pressure (external probe) – Piezoresistive
Measuring range	0 to 2000 hPa
Accuracy	±0.1 % measured value*
Resolution	0.1 Pa (0638 1347) 0.01 hPa (0638 1547) 0.001 hPa (0638 1447) 0.1 hPa (0638 1847 / 0638 1647)

Differential pressure (external probe) – Piezoresistive

Measuring range

0 to 2000 hPa

Accuracy

±0.1 % measured value*

Resolution

0.1 Pa (0638 1347)

0.01 hPa (0638 1547)

0.001 hPa (0638 1447)

0.1 hPa (0638 1847 / 0638 1647)

*Accuracy information applies only to instrument without probes connected

Differential pressure (external probe) – Ceramic
Measuring range	-1 to 400 bar
Accuracy	±0.2 % of fsv*
Resolution	0.01 bar

*Accuracy information applies only when the device does not have a measuring head connected.

General specifications
Size	219x68x50mm
Operating temperature	0 to +50 °C
Shell material	ABS
Channel	2; 1
Measurement cycle	0.04 seconds
Connect	Hose: inner Ø 4 mm outer Ø 6 mm
Battery type	9V (6LR61)
Battery life	Continuous operation with internal pressure sensor: 30 h; With rech. battery: 10 h; With carbon battery: 18 h
Screen	LCD (Liquid Crystal Display)
Display	7 segment and dot matrix
Display updates	2x per second, 4x per second rapid measurement
Power supply	Battery/Rechargeable battery, 12 V power supply
Connection protocol	RS232
Memory	100 kB; 25,000 measurement values
Storage temperatures	-20 to +70 °C
Weight	300g