Simple Continuous Level Measurement
The Liquicap FMI21 is designed for continuous level measurement where a straightforward capacitance solution is all that is required. Its rod probe measures the level of conductive liquids continuously and provides a 4–20 mA signal for integration into the control or monitoring system.
Designed for Conductive Liquids
FMI21 is intended for liquids with a conductivity of at least 30 μS/cm. Within its applicable operating range, the measurement is independent of the liquid's dielectric constant, which makes the device suitable for different conductive liquids without requiring the same level of media-specific adjustment associated with some other capacitance applications.
A Practical Solution for Tanks and Cisterns
With a maximum measuring distance of 2.5 m, the FMI21 fits smaller and medium-sized vessels where a long probe is not required. Endress+Hauser specifically positions it for cistern measurement and inventory management applications.
Suitable for Aggressive Liquids
The probe is available in 316L/1.4404 stainless steel with PP, with a carbon-fiber probe option featuring PP coating. These material choices allow the FMI21 to be used with certain aggressive liquids, including acids and alkalis, when the selected configuration is chemically compatible with the process medium.
Straightforward Process Integration
The FMI21 uses threaded process connections and provides a standard 4–20 mA output. Its factory configuration is set from 0 to 100% according to the ordered probe length, keeping commissioning relatively simple.
Built for Everyday Industrial Conditions
The device supports process temperatures from -40 to +100°C and pressures from vacuum up to 10 bar. International explosion protection certificates and WHG overfill prevention options are available depending on the selected configuration.
Key Features
- Capacitance level transmitter for continuous liquid level measurement
- Designed for conductive liquids
- Minimum liquid conductivity 30 μS/cm
- Accuracy <1%
- Maximum measuring distance 2.5 m
- Process temperature -40 to +100°C
- Process pressure vacuum to 10 bar
- 4–20 mA output
- Rod probe design
- Probe materials: 316L / PP
- Optional carbon-fiber probe with PP coating
- Threaded process connection
- Factory preconfigured from 0 to 100% according to probe length
- Measurement independent of dielectric constant within the applicable conditions
- International hazardous-area approvals available depending on configuration
- WHG overfill prevention option
Typical Applications
Water and Conductive Liquids
Continuous level monitoring in tanks containing conductive water-based liquids.
Storage Tanks
Suitable for straightforward continuous level measurement where a compact rod probe and 4–20 mA output are required.
Cisterns
The FMI21 is specifically suited to cistern measurement, providing continuous level information for storage and inventory monitoring.
Inventory Management
The instrument can be combined with remote measured-value interrogation solutions such as Endress+Hauser Fieldgate systems for inventory monitoring applications.
Chemical Storage
Suitable for selected conductive acids, alkalis and other aggressive liquids when the probe material is correctly matched to the medium.
Utility and Process Tanks
A practical option for continuous level measurement in smaller process and utility vessels.
FAQ
What is the Endress+Hauser Liquicap FMI21?
The Liquicap FMI21 is a capacitance level transmitter for continuous level measurement of conductive liquids.
What type of liquids can FMI21 measure?
FMI21 is designed for conductive liquids with a minimum conductivity of 30 μS/cm.
What is the maximum measuring range?
The maximum measuring distance is 2.5 m.
What is the accuracy of the FMI21?
The specified accuracy is less than 1%.
What are the temperature and pressure limits?
The process temperature range is -40 to +100°C, and the process pressure range is vacuum to 10 bar.
Does FMI21 use 4–20 mA?
Yes. The current official product information specifies 4–20 mA communication.
Is FMI21 suitable for non-conductive liquids?
FMI21 is specifically designed for conductive liquids, with a specified minimum conductivity of 30 μS/cm. It should therefore not be treated as a general-purpose capacitance sensor for all liquids.
Does the liquid's dielectric constant affect the measurement?
Within the applicable operating conditions, Endress+Hauser states that the measurement is independent of the liquid's dielectric constant.
What process connections are available?
The current product information lists G 1½ and NPT 1½ threaded process connections.
Is FMI21 suitable for hazardous areas?
Yes. International explosion protection certificates are available depending on the selected configuration. WHG overfill prevention is also available.
