Elcometer 309 Digital Delta T Hygrometer

The Elcometer 309 Delta T hygrometer allows simple and quick measurement of two critical climatic parameters in ceilings:

• Delta T (TΔ): The difference between the surface temperature (Ts) and the dew point temperature (Td). If TΔ is less than 3ºC , no dyeing should take place.
• Relative humidity (RH): expressed as a percentage, it is a ratio expressing the actual amount of water vapour in the air compared to the maximum amount of water vapour that the air could contain at a given temperature. Typical maximum relative humidity values specified by paint manufacturers range from 75% to 85%.

Elcometer 309 Delta T hygrometers include:

• Solid construction: Suitable for use in extreme environments, the Elcometer 309 digital hygrometer is dust and water resistant and has fully sealed sensors.
• High/low limits: Either (?) or (X) is displayed graphically on the screen with flashing red or green LEDs indicating pass or fail.
  • Delta T Temperature: TΔ is preset to >3ºC (>5ºF), which is the industry norm.
  • Relative humidity: The user can set an upper limit for the relative humidity.
• Measurement hold/release function: Measurements are "frozen" on the screen with the press of a button. They can then be saved before, by simply pressing the button again to "unlock" the screen and then take further measurements if required.
• Rear lighting: Provides clearly illuminated information - ideal in dark or confined spaces..