Volatile Matter, Specific Equipment - Precision Wet & Dry Thermometer
Precision Wet & Dry Thermometer

Operating instruction of wet and dry thermometer:

Fill the reservoir at the bottom of the wet bulb thermometer with clean, clear water, Then place the cloth attached to the wet bulb thermometer into the reservoir.
Allow enough time for the cloth to be completely wet, before reading the wet
Temperature.

When using the instrument, first take the reading of the dry thermometer, then verify
The wet thermometer reading. Subtract the wet bulb reading from that of the
Dry bulb. Find the intersection between the dry bulb temperature (oC)
And the difference in temperature (Δ oC).

For example, the temperature shown on the dry bulb thermometer is 30oC,
And 25oC on the wet bulb thermometer. The difference is 5oC.
Using 5oC as the vertical coordinate (Δ oC), and
30oC as the horizontal coordinate, the intersection point is at '64'.
This means that the air humidity is R. H. 64%.