Autonomous Level Data Loggers for Groundwater Level Measurement

In the conventional groundwater level estimation method, a conductive switch strikes the water surface and then produces an acoustic signal that determines the water depth. This method requires the presence of operators.

Autonomous level data loggers:

Today, autonomous level data loggers are designed to automatically measure groundwater levels. These loggers are equipped with a battery and are comprised of a microprocessor circuit with a storage tool and a level sensor. The data obtained from these loggers is read through a USB converter and specialized software.

Data loggers calculate the water column that is used as a basis for calculating the depth to the water surface level.

F=B-E

(F= depth-to-water surface

B=total installation depth

E= water column)

Autonomous Level Data Loggers for Groundwater Level Measurement

It is worth noting that barometric compensation is required to accurately calculate the groundwater level. The air pressure must be subtracted from the hydrostatic pressure. In conventional surface sensors, this is done with the help of a capillary, which is a tube in the surface sensor cable. But such mechanical compensation is not suitable for all environments; a second pressure sensor is needed to prevent interference in measurements. Should a second pressure sensor be used, it is only necessary to subtract the current air pressure from the measured value of the surface sensor to obtain the hydrostatic pressure. Newly designed loggers eliminate the need to measure air pressure separately. These loggers are equipped with a second sensor at the top end.

In addition to measuring hydrostatic and barometric pressure, the logger can also carry out calculations and straightly save barometrically compensated water levels and depth-to-water-surface values.

The special software of these loggers offers a variety of graphs and graphic depiction modes.