Testo 6721 Dew Point Switch

Humidity monitoring in compressed air down to -30°C.

Retired products cannot be ordered

The Testo 6740 Trace Humidity Sensor is the recommended replacement

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Part Number

0555 6721

Manufactured

By Testo

Includes

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Features

Detects moisture in compressed air systems
Measurement range -30 to 30°C (-22 to 86°F)
Optional alarm box available
Easy configuration with P2A software
Uses proven Testo humidity sensor
Mini DIN interface

The Testo 6721 dew point switch measures the temperature pressure dew point (tpd) coming from refrigeration dryers or downstream in pneumatic machines and processes from -30 to 30°C (-22 to 86°F) up to 300 psi (20 bar). Moisture in compressed air lines can lead to expensive damage: icing, corrosion, water hammer, sticky and clogged materials. The Testo 6721 dew point switch can save time, money and system downtime by monitoring moisture and avoiding damage.

The Testo 6721 dew point switch uses Testo's proven RH sensor design for accurate temperature pressure dew point measurements. It's easily installed in dryer and compressed air lines via its 1/2" NPT threaded fitting.

The Testo 6721 dew point switch can be configured using the optional Testo P2A software via USB cable and the data port on the 6721 switch. The software can easily program, adjust and review the 6721 operating history while connected to a laptop or PC. The user can even save a "master" program file that provides easy "copy and paste" program replication for OEM requirements. An optional alarm box (0554 6722) provides visual confirmation of both pre and alarm conditions.

Testo 6721 Dew Point Switch Specifications

Feature	Testo 6721
Measuring range	-30 to 30°C (-22 to 86°F)
Accuracy	±4 K (-30 to -20°C)(-22 to -4°F) ±3 K (-20 to -10°C)(-4 to 14°F) ±2 K (-10 to 0°C)(14 to 32°F) ±1 K (>0°C)(>32°F)
Sensor	Testo humidity sensor (with special trace humidity adjustment) and NTC temperature sensor
Process pressure	Max. 20 bar (abs)(290 psi)
Process temperature	0 to 50°C (32 to 122°F)
Outputs	2x switches potential-free max. 30 V/0.5 A
Interface	Mini-DIN interface (serial) for parameterization / adjustment / analysis via P2A software
Voltage supply	20 to 30 VAC/VDC