Measuring Water Level in Tanks

Water reservoirs vary greatly in size and shape. They can be service tanks used for water storage, natural "lakes" that serve as sources of drinking water, or artificially created reservoirs, for example, by constructing a dam in a river valley. The methods of measuring water level differ significantly depending on the type of reservoir being measured.

In service local reservoirs, the volume of water is usually known in advance, so by monitoring the level it is possible to control the degree of filling and water pumping, thus maintaining stable operation of the water supply system. Water withdrawal will cause the level in the reservoir to drop, resulting in the measuring device sending a signal to the pump to start pumping in order to restore the required water level. Level monitoring not only helps prevent overflow and drying out of the reservoir but also signals pump failures.

Standard level transmitters such as 26Y are suitable for such level measurement tasks. A submersible level transmitter is lowered into the measuring chamber of the service reservoir via a cable. This provides easy access to the sensor for maintenance, calibration, and relocation to a new measurement site. If the water in the reservoir is turbulent, a hydrostatic level transmitter can be installed inside a special tube. For this, a compact level meter such as 36XS, with a diameter of only 16 mm, may be required.

The water level in natural water bodies and artificially created reservoirs also requires measurement. Since such reservoirs can be extremely large and contain huge volumes of water, very accurate instruments are required for measurement, as a level change of even a few millimeters can correspond to many thousands of liters of water. In this case, to determine the volume of water at each time period, the shape of the reservoir must be taken into account, and the sensor must be extremely stable and accurate. Since the water temperature in these reservoirs can vary significantly, affecting the specific density values and, consequently, the pressure exerted on the transmitter, it may sometimes be necessary to use a sensor that also measures temperature. For such tasks, a highly accurate and stable level and temperature transmitter such as 36XW is suitable.

For measuring water in natural reservoirs, the level sensor is usually installed in a tube located in a service tower, where pump equipment used for water intake is also typically located. This tower is usually built at a location where the water intake level can be the lowest. In reservoirs created by dam construction, the intake point may be located directly in the dam structure. If the monitoring system is installed in a separate intake chamber, the equipment should be protected from the influence of water flows coming from the reservoir, as the turbulence created can cause errors in instrument readings.

Measuring water level using submersible transmitters has proven to be the simplest, most accurate, and reliable method for use in reservoirs.

If you need to select a level sensor, you can do so in the catalog or by contacting our specialists.