Dew point temperature Td (°C or °F) is the temperature at which condensation begins to form at a given constant barometric pressure, or where the relative humidity would be 100% if the air was cooled. Although dew point is expressed as a temperature, it correlates with the amount of water vapor in the air, and is therefore not dependent on ambient temperature.

Although dew point is most commonly referenced in the context of weather reporting, it is also an important factor in many industrial processes. Excess moisture can be harmful to product quality and performance, and to the materials as well. Environmental conditions can determine the effectiveness of many industrial applications, which is why monitoring the dew point is essential in many trades. Dew point is also a significant factor in HVAC, heating, drying, venting and cooling technologies.

Applications for Dew Point Meters:

  • Meteorology
  • Indoor air quality / HVAC
  • Compressed air
  • Trace moisture in gases
  • Dryers

Dew Point Measurement Technology:

Chilled mirror
Chilled mirror sensors operate by cooling a mirror until water vapor begins to condense on the surface. The temperature at which the condensation occurs is, by definition, the dew point. Chilled mirrors offer the highest accuracy of any dew point meters and are routinely used in labs and other facilities where the highest accuracy is critical. They are also often used to calibrate other types of dew point meters.

Aluminum oxide sensors
Aluminum oxide technology is designed for low dew point measurement in industrial processes. These sensors are generally small in size and can often be placed in-situ under high pressure making them particularly effective in a wide array of industrial uses.

Polymer sensors
Polymer sensors offer a wide measuring range and outstanding stability while requiring a minimum of maintenance. These instruments consist of a humidity sensor and temperature sensor from which a dew point at a given pressure is calculated. New advances– such as built-in calibration capability– have increased the accuracy level of polymer sensors making them more attractive for applications with low dew points. Polymer sensors combine the long term stability and accuracy needed for industrial applications with the ruggedness and minimal maintenance requirements for meteorological and air quality applications.

If you have any questions regarding dew point meters please don't hesitate to speak with one of our engineers by e-mailing us at or calling 1-800-884-4967.