Elcometer 309 Delta T Hygrometer




Elcometer 309 gauges are supplied complete with a Calibration Certificate (RH only), included in the price.


The Elcometer 309 Digital Delta T Hygrometer provides a simple and fast measurement of Delta T temperature and relative humidity.


*Note: If you have any questions, need further information, or require assistance with other model’s price, please don’t hesitate to contact us.


For more details, please contact us on 03-3359 0375.

Interested with This Product?

The Elcometer 309 Delta T Hygrometer provides a simple and fast measurement of the two critical climate parameters within coatings:

  • 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): Expressed as a percentage, RH is the ratio of the amount of water vapour actually held by the air compared to the maximum amount of water vapour the air could hold at a given temperature. Typical maximum RH values specified by paint manufacturers are between 75% and 85%.

The Elcometer 309 Delta T Hygrometers include:

  • Rugged design: Suitable for use in extreme environments the Elcometer 309 digital hygrometer 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 upper limit 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.
Weight 0.3 kg
Dimensions 18 × 7.5 × 3.5 cm

Technical Specification

Part Number Description Certificate
G309—-1 Elcometer 309 Delta T Hygrometer
Basic Calibration Certificate supplied as standard
Operating Range -20ºC to +80ºC (-4ºF to +176ºF)
Surface Temperature (TS) -20ºC to +80ºC (-4ºF to +176ºF)
Relative Humidity (RH) & Accuracy1 0% to 100% RH (±3%)
(Default upper limit 75%, user adjustable)
Resolution 0.1ºC (0.1ºF) / 0.1%
Power Supply 2 x AA batteries or via USB Cable
Battery Life Greater than 40 hours (Backlight off)
Dimensions 180 x 75 x 35mm (7 x 3 x 1.4”)
Weight 300g (0.66lb)
Packing List Elcometer 309 Delta T Hygrometer, wrist strap, 2 x AA batteries, protective carry case/pouch with belt clip, RH probe calibration certificate and operating instructions.

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