Elcometer 309 Delta T Hygrometer

Before painting, you need to know the parameters of the coatings. These are clearly specified on the technical data sheets drawn up by paint manufacturers.

Relative humidity (RH) and Delta T (ΔT) are two climatic values indicated on the technical data sheets.

Delta T (ΔT): difference between the dew point (Td) and the surface temperature (Ts). When the ΔT is less than 3°C, painting should not be carried out.

Relative humidity (RH): Expressed as a percentage, RH is the ratio expressing the quantity of water vapour contained in the air compared to the maximum amount of water vapour that the air can contain at a defined temperature. The usual maximum RH values specified by paint manufacturers range from 75% to 85%.

The Elcometer 309 Delta T Hygrometer allows these two important quantities to be measured quickly and easily.

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• Robust design: With its perfectly sealed sensors, the Elcometer 309 is waterproof and dustproof. It can be used in the most extreme environments.
• Upper/Lower Limits: These are shown on the display with a (?) or (X) sign and a red or green LED flashes to indicate whether the measurement is Accepted or Rejected.
• Delta T temperature: the ΔT is preset to a value >3°C, in accordance with the industry standard.
• Relative humidity: the user can define a maximum value for RH.
• Locked/released measurement function: at the touch of a button, measurements on the screen can be locked and saved; then, by pressing the button again, the screen can be released to take new measurements, if required.
• Backlighting: Allows information to be read in the dark or in confined spaces.