Application
The Waterpilot FMX21 is a pressure sensor for hydrostatic level measurement.
Endress+Hauser offers three different versions of the device:
- FMX21 with a stainless steel housing, external diameter of 22 mm (0.87 in): This version is excellently suited to drinking water applications and for use in bore holes and wells with small diameters
- FMX21 with a stainless steel housing, external diameter of 42 mm (1.65 in): Heavy-duty version and easy to clean thanks to flush-mounted process isolating diaphragm, ideally suited to wastewater and wastewater treatment plants
- FMX21 with plastic insulation, external diameter of 29 mm (1.14 in): Robust version for use in salt water and excellently suited to applications on ships (e.g. ballast water tanks)
Your benefits
- High resistance to overload
- High-precision, robust ceramic measuring cell with long-term stability
- Climate proofed sensor thanks to completely potted electronics and 2-filter pressure compensation system
- Simultaneous measurement of level and temperature with optionally integrated Pt100 temperature sensor
- Accuracy
- Standard reference accuracy ±0.2 %
- PLATINUM version ±0.1 %
- Automatic density compensation to increase accuracy
- Usage in drinking water: KTW, NSF, ACS
- Approvals: ATEX, FM, CSA
- Marine approvals: GL, ABS, BV, DNV
- Extensive range of accessories provides complete measuring point solutions
Measuring Principle
The ceramic measuring cell is a dry measuring cell i.e. the pressure acts directly on the robust,
ceramic process isolating diaphragm of the Waterpilot FMX21. Changes in air pressure are guided
via a pressure compensation tube through the extension cable to the rear of the ceramic process
isolating diaphragm and are compensated for. A pressure-dependent change in capacitance, caused
by the movement of the process isolating diaphragm, is measured at the electrodes of the ceramic
carrier. The electronics unit then converts this to a signal that is proportional to the pressure and
linear to the level.