TM 5-3610-253-14
7-6.
OPERATION UNDER USUAL CONDITIONS.
NOTE
Be sure psychrometer is not close to fans, heaters, open doors, and
ventilation ducts.
a.
Check that water level in cistern is halfway between brackets.
b. Add distilled water to saturate wick and fill cistern when necessary.
c.
Mount psychrometer on hook on wall.
d. Wait five minutes before recording WET and DRY bulb readings.
e.
Convert WET and DRY bulb thermometer readings to relative humidity as follows:
Air Temperature (DRY Bulb): 68°F
WET Bulb:
62° F
Depression = DRY Bulb (t) - WET Bulb (tl) = 68°- 62°= 6°
Depression = 6°F
Use left column to find air temperature of 68°F.
Use top column to find depression of 6°F.
The intersection of both columns gives the percent of relative humidity,
in this case 71%.
7-6
