Starting at $1,473.00
Starting at $1,325.70

Not in stock. Usually ships in 3-5 business days [?]

Need Help? Call 1-800-884-4967
Mo-Th 8am to 5:30pm. Fr 8am to 5pm ET


  • Pressure Dew Point Temperature: -60 to 30°Ctpd
  • Temperature Range: 0 to 50°C
  • Atmospheric Dew Point: -80 to -15°Ctd (at 30 bar rel.); -70 to +10°Ctd (at 3 bar rel.); -60 to +30°Ctd (at 0 bar rel.)
  • Pressure Resistance: Up to 50 bar absolute
  • Analog Output Signal: 4-20 mA (2-wire)
  • Scaling: Freely scalable via display/buttons
  • Output Variables: °Ctpd, °Ftpd, °CtA (atm. dew point), °FtA, %RH, ppmv, mg/m3, °C, °F
  • Resolution: 12 bit
  • Accuracy: ±40µA

The Testo 6740 trace humidity sensor monitors moisture levels in air and compressed gasses. The Testo 6740 two-wire unit provides a scalable 4-20mA output signal and can be ordered with or without a local display. Calibrated to ±1% relative humidity and long-term sensor stability makes the 6740 ideal for monitoring compressed air dryers and preventing system damage from condensing water vapor.

The Testo 6740 trace humidity sensor can be configured for a variety of applications. An optional connecting plug can be added to the Testo 6740 to provide 2 limit signal alarms with LED status outputs to ensure your process is within tolerance. The sensor can be installed directly in-line or combined with measuring chamber and cooling coils to suit specific application.

The Testo 6740 housing rotates 350° and can be ordered with a ½" NPT or G1/2 process connection for ease of installation. The Testo 6740 is a simple, flexible, and cost effective sensor for trace humidity monitoring.

Testo Connection Plug
Connection plug with 2 alarm points for Testo 6740 Series Trace Humidity Sensor
Testo Measurement Chamber
Measuring Chamber for Testo Dew Point Transmitters
Testo Cooling Coil
Cooling coil for Measuring Chamber


This product can be used in the following applications: