Description

 

The TESTO 521-3 Differential Pressure Meter 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 m/s.

TESTO 521-3 Differential Pressure Meter 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)

Technical Data

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 to instrument without probes 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

*Accuracy information applies only to instrument without probes 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 % of mv) (20.1 to 250 Pa)
Resolution	0.1 Pa
Static pressure	1000 hPa
Overload	50 hPa
Zeroing	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 % of mv*
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 to instrument without probes connected

General technical data
Dimensions	219 x 68 x 50 mm
Operating temperature	0 to +50 °C
Product-/housing material	ABS
Channels	2; 1
Measuring rate	0.04 s
Connection	Hose: inner Ø 4 mm outer Ø 6 mm
Battery type	9 V (6LR61)
Battery life	Continuous operation w/ internal pressure sensor: 30 h; With rech. battery: 10 h; With carbon battery: 18 h
Display type	LCD (Liquid Crystal Display)
Display function	7 segment display and point matrix
Display update	2x per second, in fast measurement 4x per second
Power supply	Battery/Rechargeable battery,Mains unit 12 V
Interface	RS232
Memory	100 kB; 25,000 measuring values
Storage temperature	-20 to +70 °C
Weight	300 g