Manual Sasa Open Pan Evaporimeter For Weather Monitoring, Measuring Evaporation Rate

introduction

the pan evaporimeter is designed as per the guidelines provided in is: 5973-1970. pan evaporimeter is used for the measurement of the amount of the water evaporated from the soil, and from the free water surfaces. for the ease of calculation, the rate of evaporation is defined as the amount of water lost by the evaporation from the area of the surface, in the unit time. here the unit time is normally one day and unit depth is one millimeter.

construction

the pan evaporimeter comprises chiefly of a cylindrical reservoir made of g.i./copper sheet of 1 mm thickness. a fixed point gauge is used to indicate the level of water in the pan, and calibrated measuring cylinder is used to add water to, or remove water from the pan (in case of rains) prior to each observation to maintain the level of water up to the fixed point gauge. the reservoir is covered by expanded metal grating to protect the water from animals and birds. a thermometer is also suspended in the water to record the temperature at the time of the observation.

specifications

material reservoir: g.i. sheet 1 mm thick

thermometer: alcohol

measuring cylinder: stainless steel

top cover: expanded metal sheet