Wet And Dry Bulb Hygrometer Principle

The device contains two thermometers.

Wet and dry bulb hygrometer principle.

4 0 out of 5 stars 1. Dry and wet bulb hygrometer. A hygrometer is an instrument used to measure the amount of water vapor in air in soil or in confined spaces. As the water around the wet bulb evaporates the bulb cools down because the water absorbs heat from its surroundings as it changes phase.

Get it thu sep 24 tue sep 29. One is dry and the other is kept moist by wrapping the bulb in a wet piece of cloth. Wet dry bulb hygrometer wall mounted thermometers eisco labs. Hygrometer contains two thermometers one is called dry bulb and second as wet bulb.

Humidity measurement instruments usually rely on measurements of some other quantities such as temperature pressure mass a mechanical or electrical change in a substance as moisture is absorbed. As our testing lab is not air conditioned so the dry bulb hygrometer is of course need for the accurate of all expects. Bulb as the water evaporates and the wet bulb temperature becomes lower than the air dry bulb temperature. An important condition is that correct accurate measurement of wet bulb temperature is obtained only if air moves with velocity around the wet wick.

At a lower humidity water evaporates more actively so that the wet bulb temperature lowerssharply. Masons wet dry bulb hygrometer is used to calculate the water vapour content relative humidity of air at a given temperature. Only 9 left in stock order soon. Moreover it is the most common hygrometer and easily usable.

Wet and dry bulb psychrometers are the most simple and common way of measuring humidity. Evaporation from the water on the wet bulb causes its temperature reading to drop causing it to show a lower temperature than the dry bulb. 76 70 65 70 76 70 76 70 70 76 10 71 9. In order to measure the dry bulb and wet bulb temperature the psychrometer frame glass covering thermometer arrangement is rotated at 5 m s to 10 m s to get the necessary air motion.

The wet bulb thermometer has it s bulb wrapped in a tight fitting muslin cloth material wicking which is soaked in. This type of hygrometer uses two basic mercury thermometers one with a wet bulb one with a dry bulb. The instrument is made up of two indentical thermometers one a wet bulb and the other a dry bulb. The principle behind a psychrometer is fairly simple.

Dry bulb reading wet bulb reading difference r h. From table mean r h.