Starting at $1,785.00 Starting at $1,606.50
  • Usually ships in 3-5 business days



  • 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.


This product can be used in the following applications: