Technical Characteristics and Environmental Adaptability
-
High-Purity Ceramic Sensor: The 99.9% Al2O3ceramic cell is dry and oil-free, offering superior long-term stability and resistance to mechanical abrasion or chemical attack. It is virtually immune to the pressure peaks that often damage metal diaphragms.
-
Intelligent Density Compensation: Through HART 6.0, the FMX21 can perform temperature-compensated density correction. This ensures that the level reading remains accurate even if the water temperature—and therefore its density—changes significantly.
-
Climate-Proof and Robust: The electronics are completely potted to prevent moisture ingress, and the device utilizes a dual-filter pressure compensation system. This makes the sensor “climate proofed” against the internal condensation that often plagues submersible probes.
-
Versatile Application Versions: The FMX21 is available in three distinct builds:
-
Drinking Water: Slim 22mm (0.87″) diameter for boreholes; certified by ACS, KTW, and NSF.
-
Wastewater/Sewage: Robust 42mm (1.65″) version designed to resist fouling and heavy build-up.
-
Saltwater: Specialized materials for high-salinity environments and marine applications.
-
-
Integrated Temperature Measurement: An optional Pt100 sensor is integrated directly into the probe, providing high-accuracy temperature data alongside the level signal.
Technical Specification Matrix
| Feature | Technical Details |
| Measuring Principle | Hydrostatic Pressure |
| Measuring Cell | Capacitive Ceramic (99.9% Al2O3) |
| Accuracy | ±0.2% (Standard); “Platinum” ±0.1% |
| Measuring Range | 0 to 20 bar / 200 m $H_2O$ (0 to 300psi / 600ft H2O |
| Output | 4…20mA HART 6.0 |
| Probe Diameter | 22 mm (Standard/Drinking water) or 42 mm (Wastewater) |
| Approvals | ATEX, FM, CSA, Marine (GL/ABS/LR), Drinking Water |
Primary Applications
-
Groundwater and Boreholes: Precision monitoring in narrow wells where high accuracy and long-term stability are required.
-
Wastewater Treatment: Level control in primary tanks, sludge digesters, and lift stations using the heavy-duty 42mm version.
-
Desalination and Marine: Monitoring levels on ships or in coastal saltwater intake structures.
-
Drinking Water Production: Management of reservoirs and dams where integrated temperature data helps monitor water quality.
-
Process Tanks: Hydrostatic measurement in open or vented tanks containing aggressive chemicals compatible with ceramic and the chosen cable material.
