DPT146 Dewpoint and Pressure Transmitter for Compressed Air

The Vaisala Dewpoint and Pressure Transmitter DPT146 for Compressed Air makes monitoring compressed air simple and convenient.

The DPT146 measures both dew point and process pressure simultaneously, and is ideal choice for anyone using or monitoring compressed air.

  • The first transmitter that monitors both dew point and process pressure
  • A simple and convenient transmitter for monitoring of compressed air
  • Highly accurate humidity information thanks to dew point data coupled with live pressure input
  • Proven sensor technology
  • Compatible with the Vaisala Hand-Held DM70 for easy spot checking, local display and data logging
  • Pressure: 1…12 bar
  • Dew point: -60 ... +30 °C (-76 ... +86 °F) Tdf with accuracy of  +/- 2 °C (+/- 3.6 °F)
  • Digital output RS-485 with MODBUS
DPT146 Dewpoint and Pressure Transmitter for Compressed Air

DPT146 Dewpoint and Pressure Transmitter for Compressed Air

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.