Whirling Hygrometer

Simple to use, just open the wick container wet the wick thoroughly, ensuring that the wick on the thermometer bulb is wet. Then holding the thermometer case horizontally, rotate the instrument for 15 to 20 seconds.

Record temperatures of the wet bulb first and then the dry bulb and calculate the wet bulb depression- this is the difference between the two readings.

Then using the enclosed chart look where the wet bulb depression is to determine the % relative humidity.

No battery required.

Utilising wet and dry bulb mercury-filled thermometers this professional whirling hygrometer (sling psychrometer) offers the maximum level of accuracy.

The thermometer tubes measure temperature over the range of 0 to +50°C enabling the % RH to be calculated using the chart supplied.