Question

What is an atmometer?

Answer 1

Hint: This is a device to measure the quantity of water evaporated from an open water surface or from the ground. This is usually made with a filter paper which can draw water from easily measurable sources.

Complete step by step answer:
Atmometer:
- This is an instrument that can give a direct measurement of evaporation which basically consists of a wet, porous ceramic cup mounted on the top of the cylinder water reservoir.
- The ceramic cup is covered with a green fabric that stimulates the canopy of a cup.
- As water evaporates from the surface, more water is drawn from the source through the wick by capillary action to replace the water lost by evaporation.
- The reservoir tube is filled by distilled water that evaporates out of the ceramic cup and is pulled through a suction tube that extends to the bottom of the reservoir.
- Underneath the fabric, the ceramic cup is present which is covered by a special membrane that keeps mixing rainwater from seeping into the ceramic cup.
- A rigid wire extending out from the top to keep birds from perching on top of the gauge.

Additional information:
- Instruments used in evaporation:
Atmometers
Evaporation pans and tanks
Evapora- Transpirometer or lysimeter
- Potential evaporation:
This is the quantity of water vapour which could be emitted by a surface of pure water, per unit surface area and unit time, under existing atmospheric conditions. This is expressed as the mass or volume of liquid water evaporated per area in unit time.

Note:
- Heat or energy is necessary for evaporation to occur. Energy from the heat is used to break down the bonds that hold water together, which is why water easily evaporates at boiling point but evaporates slowly at the freezing point.
- Evaporation and transcription jointly called evapotranspiration or ET is one of the components of the hydrologic cycle. The loss of water in the form of vapours from soli, snow, lake, stream and depressions to the atmosphere due to the energy of the sun is called evaporation.
- Transpiration is the process by which water leaves the living plants body and enters the atmosphere.