FMB51

Hydrostatic Level Transmitter Measuring Principle The hydrostatic level transmitter detects liquid level by measuring the static pressure generated by the liquid column. The basic principle is based on the formula P = ρ·g·H + P₀. When the liquid density remains constant, the atmospheric pressure is introduced into the sensor's negative pressure chamber through the vent tube to compensate for atmospheric pressure (P₀). The liquid hydrostatic pressure (P) is then directly proportional to the liquid level height (H). The process pressure acts directly on the internal sensing element, such as a ceramic process isolation diaphragm. The pressure compensation tube transfers atmospheric pressure variations to the back side of the sensing element for compensation. The deformation of the sensing element generates a capacitance change proportional to the applied pressure. This capacitance change is converted into a pressure-proportional electrical signal. Since the pressure signal has a linear relationship with the medium level, the signal is processed through temperature compensation and linearization, and finally output as a standard 4–20 mA signal.

Economical

Deltapilot FMB51 Rod Version Sensor uses a CONTITE measuring cell with a fixed process connection. It is mainly designed for environmental applications. It is suitable for level measurement of liquids or slurries in open or closed vessels, with measurement unaffected by foam. The design complies with IEC 61508 and meets SIL2 functional safety requirements.