Wet & Dry Bulb Hygrometer
CM3505 User Guide
The ClimeMET Wet & Dry Bulb Hygrometer measures relative humidity.
Getting Started
There are two mounng hooks at the top and boom of the Hygrometer.
These can be used to hook your Hygrometer onto a xing, or to screw your Hygrometer
to a wall or fence post. Place the Hygrometer at least 1.5 metres above the ground.
Avoid any areas that may be subjected to extreme heat or cold.
To get started, open the protecve cover at the boom of the Hygrometer and remove
the water tank. Fill the water tank with ltered water or clean rain water and place back
into the Hygrometer. Aach the wick to the base of the wet thermometer (like a sock),
and then gently feed the other end of the wick through the hole into the water tank.
Once this is done, place the Hygrometer in your desired locaon and wait at least 1
hour to take a reading.
Taking a Reading
To take a reading, you’ll need the Hygrometric Conversion Table that came with your
Hygrometer to determine the % relave humidity. This is calculated from the dry bulb
temperature and the wet bulb depression.
Record the temperature of the wet bulb and then the dry bulb. Subtract the wet
temperature from the dry temperature. This will give you the depression of the wet
bulb. Using the dry temperature and the wet bulb depression, nd your relave
humidity reading at the point where these two values meet on the conversion table.
An example is shown below.
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0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0
-1 90 79 69 59 49 39 30 20 10 1
0 90 81 71 61 52 44 34 25 16 7
1 90 81 73 64 55 47 38 29 20 13 4
2 91 82 73 64 57 49 41 33 24 17 9 1
3 91 83 74 65 57 49 43 36 28 21 14 7
4 92 83 75 67 59 51 43 35 32 25 18 11 4
5 92 84 76 68 61 53 46 38 31 24 21 15 8 2
6 92 85 77 70 62 55 48 41 34 27 20 14 12 6
7 93 85 78 71 64 57 50 44 37 30 24 17 11 5
8 93 86 79 72 65 59 52 46 39 33 27 21 15 9 3
Depression of Wet Bulb °C (Dry Bulb Temperature minus Wet Bulb Temperature)
Dry Bulb Temperature (°C)
