DMT143 Miniature Dewpoint Transmitter for OEM Applications

The Vaisala DRYCAP® Dewpoint Transmitter DMT143 is a miniature dew point measurement instrument. 

The transmitter can be installed directly into pressurized systems at 50 bar (725 psia) maximum pressure.

  • Miniature size dew point transmitter for e.g. small industrial dryer applications
  • Vaisala DRYCAP® technology with auto-calibration
  • Long calibration interval saves maintenance costs
  • Dew point measurement range -60...+60 °C (-76...+140 °F)
  • Accuracy ±2 ºC (±3.6 ºF)
  • Withstands condensation
  • Fast response time
  • Compatible with Vaisala DRYCAP® Hand-Held Dewpoint Meter DM70
  • NIST traceable calibration (certificate included)
  • Easy servicing and data transfer via the RS485 user interface
  • LED alarm for exceeded dew point level

DMT143 Miniature Dewpoint Transmitter for OEM Applications 




Operating Principle

DRYCAP’s unrivalled performance is based on two innovations: the proven capacitive thin-film polymer  sensor and the auto-calibration function. The sensor’s thin-film polymer absorbs or releases water vapor as the surrounding humidity increases or decreases.

The dielectric properties of the polymer change as the humidity around the sensor changes, as does the capacitance of the sensor. Capacitance is converted into a humidity reading. The capacitive polymer sensor is bonded together with a temperature sensor, and dew point is calculated from the humidity and temperature readings.

Vaisala’s patented auto-calibration function optimizes the measurement stability at low dew points. The sensor is heated at regular intervals during the automated auto-calibration procedure.

The humidity and temperature readings are monitored as the sensor cools to ambient temperature, with offset correction compensating for any potential drift. This enables the DRYCAP sensor to deliver accurate measurements in the long term, dramatically reducing the need for maintenance.