Dry And Wet Bulb Psychrometer Pdf

Determine the properties of the air at state point 2 and compare them with those at state point 1.

Dry and wet bulb psychrometer pdf. The wet bulb dry bulb technology psychrometer introduction wet and dry bulb temperature measurement is a commonly used and widely accepted technique for controlling relative humidity in environmental chambers. Is cooling whereas wet bulb temperature represents how much moisture the air can evaporate. Since both the thermometers are placed side by side the mositure from wet wick may affect the readings of dry bulb thermometer to avoid this the wet bulb thermometer is placed at the lower level. Relative humidity is measured using a device called a sling psychrometer this consists of 2 side by side conventional thermometers one of which the wet bulb thermometer has a wetted wick placed at the bottom the other the dry bulb thermometer has no wetted wick.

If the air is flowing at a rate of 2 meters per second determine the drying. A sling psychrometer consists of two thermometers. Dry bulb temperature and 57 c wet bulb temperature experiences a temperature drop of 3 c as it passes through the 1 2 m wide stack of lumber. Meteorological instrument center japan meteorological agency an operational equilibrium temperature exists for the instrument depending upon.

The size of the wet bulb wick covering but is slightly dependent on ventilation rate and to an even minor degree on psychrometer design size and dimension of the dry and wet bulb ambient temperature and rh however when ventilation is in excess of 2 5 m s 1 and particularly in the. Difference between the dry bulb and wet bulb temperatures related to the ambient humidity. Relative humidity can be found by subtracting the temperature on the wet bulb thermometer from the temperature on the dry bulb thermometer and using a relative humidity chart. Astm standard e 337 02 2007 reviews in great detail the wet and dry bulb technique.

A psychrometer measures humidity by taking both a wet bulb and a dry bulb temperature reading. The uncovered thermometer measures dry bulb temperature while the one covered with wet cloth measures wet bulb temeprature. With those two values known the other properties of the air including its moisture content can be determined by computation or by reading a psychrometric chart. A psychrometer consists of two thermometers with the bulb of one thermometer covered with a wet cloth.

One is a wet bulb and the other is a dry bulb. Where a is the psychrometric coefficient which is independent of the evaporating surface area i e. When the psychrometer is swung around by its attached chain or handle the air causes the water on the wick to evaporate which. Mengshen digital psychrometer handheld backlight temperature humidity meter gauge with dew point and wet bulb temperature battery included m350 4 0 out of 5 stars 148 32 99 32.