Reliable Capacitance Measurement in Difficult Liquids
The Endress+Hauser Liquicap FMI51 is designed for continuous level and interface measurement in liquids, with a fully insulated rod probe that makes it particularly suitable for build-up forming media and high-temperature applications.
Unlike a basic capacitance probe, the FMI51 is designed to maintain dependable measurement in process conditions where coating, temperature and changing liquid properties can make level measurement more challenging.
Measurement Less Affected by Changing Media Properties
One of the useful characteristics of the FMI51 is that its measurement can be independent of the liquid's dielectric constant when the liquid conductivity is at least 100 μS/cm.
This allows different liquids to be measured without recalibration when their dielectric properties change within the applicable conditions. For processes involving changing media, this can make the instrument easier to keep in service over time.
Built for Build-Up Forming Media
The fully insulated rod probe is particularly well suited to liquids where material can accumulate on the probe.
The FMI51 is designed to continue providing level information in build-up forming media, making it a practical choice for processes where keeping the probe completely free of deposits is difficult.
High Temperature Capability
The FMI51 is designed for demanding thermal conditions, with a specified process temperature range of -80 to +200°C.
Combined with its fully insulated probe construction, this makes the FMI51 suitable for applications where conventional level measurement technologies may need to cope with elevated process temperatures.
Designed for Pressurized Processes
The instrument supports process pressures from vacuum up to 100 bar, giving it a broad operating range for industrial liquid applications.
The maximum measuring range is 0.1 to 4.0 m, allowing the probe to be selected for different tank dimensions and measurement requirements.
Key specifications:
- Measurement principle: Capacitance
- Application: Continuous level and interface measurement in liquids
- Repeatability: 0.1%
- Measuring range: 0.1…4.0 m
- Process temperature: -80…+200°C
- Process pressure: Vacuum…100 bar
- Main wetted parts: 316L, PTFE/PFA insulation
Flexible Installation for Different Process Designs
The FMI51 is available with threaded and flange process connections, allowing it to be integrated into different tank and vessel designs.
Its rod-probe construction is particularly appropriate for continuous measurements where a rigid probe can be installed directly into the process vessel.
Suitable for More Than Simple Level Measurement
The FMI51 is designed for both continuous level measurement and interface measurement in liquids.
This makes it useful not only for monitoring the amount of liquid in a vessel, but also for applications where the boundary between two liquid phases needs to be monitored.
A Practical Choice for Demanding Level Applications
The value of the Liquicap FMI51 is not simply its capacitance measuring principle. Its combination of fully insulated probe construction, high-temperature capability, resistance to build-up effects and reduced dependence on dielectric constant makes it a particularly useful option for difficult liquid applications.
Key Features
- Continuous level and interface measurement in liquids
- Fully insulated rod probe
- Suitable for build-up forming media
- Process temperature -80…+200°C
- Process pressure vacuum…100 bar
- Measuring range 0.1…4.0 m
- Repeatability 0.1%
- Measurement independent of dielectric constant under applicable conductivity conditions
- No recalibration required for different liquids under applicable conditions
- Main wetted material 316L
- PTFE/PFA insulation options
- Threaded and flange process connections
- International explosion protection certificates
- WHG overfill prevention, SIL, hygienic and marine approvals available
Typical Applications
High-Temperature Liquid Measurement
Suitable for continuous level measurement in processes operating at temperatures up to 200°C.
Build-Up Forming Media
A good fit for liquids where material deposits can form on the probe during normal operation.
Continuous Tank Level Measurement
For monitoring liquid level in tanks and vessels across a measuring range of up to 4 m.
Liquid Interface Measurement
Suitable for applications requiring continuous measurement of the interface between liquids.
Inventory Management
The FMI51 can also be used as part of Endress+Hauser inventory management solutions when combined with the appropriate system components.
FAQ
What is the Endress+Hauser Liquicap FMI51 used for?
The FMI51 is a capacitance level instrument for continuous level and interface measurement in liquids, particularly in applications involving build-up forming media and high temperatures.
What is the measuring range of the FMI51?
The specified measuring range is 0.1 to 4.0 m.
What temperature can the Liquicap FMI51 handle?
The specified process temperature range is -80 to +200°C.
What is the maximum process pressure?
The FMI51 supports process pressure from vacuum up to 100 bar.
Is the FMI51 suitable for media that cause build-up?
Yes. Endress+Hauser specifically positions the FMI51 for build-up forming media, which is one of the applications where its fully insulated rod probe is particularly useful.
Does the liquid's dielectric constant affect measurement?
Under the applicable conditions, the measurement is independent of dielectric constant when the liquid conductivity is 100 μS/cm or higher. This can allow different liquids to be measured without recalibration when the relevant process conditions are maintained.
Can the FMI51 measure liquid interfaces?
Yes. The FMI51 is designed for both continuous level and interface measurement in liquids.
What materials are used for the probe?
The main wetted parts include 316L, while the probe insulation is available in PTFE and PFA depending on the configuration.
