The EDN.369 pressure transmitter is designed for water level measurement based on the hydrostatic pressure principle. Assuming a specific gravity of 1 for pure water, the device measures the pressure applied to the sensor and converts it into water level data. For fluids lighter than water, such as oil or other liquids, the corresponding specific gravity can be stored as a default parameter in the controller or control unit for accurate level calculation.

Since pressure-based level measurement is affected by atmospheric pressure fluctuations, it is essential to use a pressure sensor with built-in barometric compensation. In addition, level measurement in storage tanks for water, oil, or similar fluids requires an open tank configuration. For closed tanks, where internal air density may vary, the use of a differential pressure transmitter is recommended.

The transmitter cable must include a vent tube to compensate for atmospheric pressure changes. As the supplied cable is permanently integrated during manufacturing, it cannot be extended later. Therefore, the total cable length from the sensor to the final signal receiving point must be specified at the time of order. Cutting and extending the cable afterward is not possible.

The EDN.369 features a socket connection that supports various thread types, allowing flexible installation. It can be mounted externally on piping systems or integrated into block structures for direct measurement in submerged or outdoor environments. The pressure sensor element is made of stainless steel, ensuring compatibility with non-corrosive liquids such as water and oil.

For applications such as level measurement of air, water, or oil, as well as pressure measurement in pipelines, the EDN.369 can be directly installed using the threaded pressure port. The transmitter is rated IP68 for reliable outdoor use. Available accuracy classes include 0.5%, 0.35%, 0.25%, 0.15%, and 0.1% F.S., depending on application requirements.

[Technical specifications]

■ Definition of Hydrostatic Pressure

P = ρ g h+ Po

            Ρ : the total pressure on an object submerged in a fluid

            g : the acceleration due to gravity

            Po : the pressure at the fluid’s surface

            (For example, 100 cm deep = 100 mbar)