Geneq > Materials Testing > Humidity - Air
Elcometer 309 Delta-T Hygrometer
 


Before painting, the coater must meet the coatings’ parameters. These are clearly specified on the paint manufacturer’s product data sheet. Relative Humidity (%RH) and Delta T (TΔ) are the two climatic values which are specified on data sheets. The Elcometer 309 Delta T Hygrometer provides a simple and fast measurement of these two critical characteristics.
  • Delta T (TΔ): The difference between the surface temperature (Ts) and the dewpoint temperature (Td). When TΔ is less than 3ºC (5ºF) painting should not occur.
  • Relative Humidity (RH): This is the amount of water vapour taken up by air. Expressed as a percentage, %RH, and is dependent on the air temperature. Typical RH values, specified by paint manufacturers, are between 75% and 85%.
  • Rugged design : Suitable for use in extreme environments the Elcometer 309 is dustproof and waterproof with fully sealed sensors.
  • High / Low Limits: Displayed on screen graphically as either () or (X) with flashing Red or Green LED’s to indicate pass or fail.
    • Delta T temperature: TΔ is pre-set at >3ºC (>5ºF), the industry norm.
    • Relative Humidity: User definable limits can be set for %RH.
  • Measurement Hold / Release function: With a single button press readings are ‘frozen’ on the screen. These can then be recorded before, simply pressing the button again to ‘unfreeze’ the screen and then take further readings as necessary.
  • Backlight : Provides clearly lit information – ideal in dark or confined spaces.

Climatic Testing
The monitoring of climatic conditions such as temperature, relative humidity, dewpoint and moisture when coating is vital to the lifetime performance of the coating. In the protective coatings industry, moisture can form on the surface when the surface temperature is low enough to cause condensation from the atmosphere. The Dewpoint Temperature (Td) is the point at which this occurs. Monitoring the surface temperature (Ts) relative to the air temperature (Ta) and its relative humidity (%RH) allows the dewpoint temperature to be calculated and compared to the surface temperature. The difference in temperature (TΔ) is the key parameter dictating when it is safe to apply the coating.

At a glance :
• Reliable TΔ and %RH readings in a single, user-friendly gauge without the need for additional equipment.

Technical Specification

Spare & accessories