DMT242 Dewpoint Transmitter for OEM Applications

The Vaisala DRYCAP® Dewpoint Transmitter DMT242 provides reliable and stable measurements for industrial dryer applications. It is designed for extreme conditions.

  • Ideal choice for low dew point industrial dryer applications
  • Incorporates advanced Vaisala DRYCAP® Sensor and enhanced auto-calibration software
  • Long-term stability in low dew points
  • Fast response time
  • Wide dew point measurement range from -60…+60 °C (-76…+140 °F) with an accuracy ±2 °C (±3.6 °F)
  • Withstands condensation
  • IP65(NEMA 4) housing provides protection against dust, dirt and splashed water
  • Can be installed directly into systems at 20 bar maximum pressure
  • NIST traceable (certificate included)
  • Compatible with Vaisala DRYCAP® Hand-Held Dewpoint Meter DM70
  • Optional loop powered display, Nokeval 301
 DMT242 Dewpoint Transmitter for OEM Applications

DMT242 Dewpoint Transmitter for OEM Applications




Operating Principle

DRYCAP’s unrivaled 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.