Pressure gauge – testo 521-1

The testo 521-1 differential pressure gauge is used for accurate differential pressure measurements on air conditioning and ventilation systems. This device is ideal for measuring pressure drop on filters and testing fans and extractors. The testo 521-1 can also perform measurements in ventilation ducts or process air using a Pitot tube (measuring range 5 to 100 m/s).

testo 521-1 also integrates a temperature compensated differential pressure sensor with an accuracy of 0.2 %fv. Additionally, you can add up to 2 compatible probes (optional to order) to the testo 521-1. The measuring heads you can choose from include:

Provide cover: Testo 521-1 differential pressure gauge, battery and factory test paper.

Outstanding features of the testo 521-1 differential pressure gauge

Technical specifications of testo 521-1

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 only applies when the probe is not connected

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

Resolution

0.1°C

*Accuracy information only applies when the probe is not connected

Differential pressure (internal sensor) – Piezoresistive
Measuring range	0 to 100 hPa
Accuracy	±0.2 % of fsv
Resolution	0.01 hPa
Static pressure	1000 hPa (pressure)
Overload	300 hPa
Zeroing	to 2.5 hPa

Differential pressure (external measuring head) – 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 measuring head) – 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 only applies when the probe is not connected

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

*Accuracy information only applies when the probe is not connected

General specifications
Size	219x68x50mm
Operating temperature	0 to +50 °C
Structural materials	ABS
Number of connection channels	2 external channels 1 internal channel
Measurement cycle	0.04 seconds
Connect	Hose: inner Ø 4 mm outer Ø 6 mm
Battery type	9V (6LR61)
Battery life	Continuous operation w/ internal pressure sensor: 30 h; With rec. battery: 10 h; With carbon battery: 18 h
Screen type	LCD (Liquid Crystal Display)
Display function	7 segment display and point matrix
Display updates	2x per second, for fast measurement 4x per second
Power supply	Battery/Rechargeable battery, 12 V power supply
Interface	RS232
Memory	100 kB; 25,000 measurement values
Storage temperatures	-20 to +70 °C
Weight	300g