FMU90 Ultrasonic Level Transmitter Overview
FMU90 is an ultrasonic level transmitter launched by Endress+Hauser, supporting the DP (differential pressure) version, and is widely used in level measurement in water treatment, chemical, food, and other industries. This transmitter can be paired with Prosonic series ultrasonic sensors to achieve non-contact continuous level measurement.
This article provides the download of the FMU90 Chinese Manual DP Version and summarizes key installation, commissioning, and parameter setting points for the quick reference of engineering technicians and procurement.
Download FMU90 Chinese Manual DP Version.pdf
Product Features and Core Advantages
- Non-contact measurement: ultrasonic principle, not affected by medium density or viscosity.
- Multi-parameter display: can simultaneously display level, distance, volume, flow, etc.
- DP version: supports differential pressure measurement mode, suitable for open or closed vessels.
- Flexible output: 4-20mA, HART, Profibus DP, and other signals are optional.
- Chinese interface: built-in Chinese menu for convenient on-site operation.
Installation and Wiring Guide
Installation Position Selection
During installation, ensure that the sensor is perpendicular to the liquid surface and avoid installing it near the feed inlet or agitator to prevent false echoes. For the DP version, pay attention to the correct connection of the high and low pressure sides.
- Keep the distance between the sensor and the vessel wall greater than 100mm.
- Avoid installing it in the exact center of the tank top to reduce multiple echoes.
- For outdoor installation, it is recommended to add a sunshade.
Electrical Wiring Steps
- Disconnect the power supply to ensure safety.
- Open the transmitter housing to expose the terminal block.
- Connect the power cable, signal cable, and sensor cable according to the manual markings.
- Check that the wiring is secure, restore the housing, and power on.
Note: The DP version requires correct distinction of the +/- pressure sides; reverse connection will cause measurement errors.
Parameter Setting and Commissioning
Basic Parameter Setting
Enter the menu through the panel keys or HART handheld communicator, and set tank shape, medium properties, measuring range, etc. in sequence. For the DP version, it is also necessary to set the differential pressure zero point and full scale.
Commissioning Steps
- Enter the main menu and select quick setup.
- Enter the empty tank height and full tank height.
- Set the output current range (e.g., 4-20mA corresponds to 0-100%).
- Save the parameters and return to the measurement interface.
- Observe whether the displayed value matches the actual level, and perform false echo suppression if necessary.
Technical Parameters Quick Reference Table
| Parameter | Specification |
|---|---|
| Measuring principle | Ultrasonic |
| Measuring range | 0-20m (depending on sensor) |
| Output signal | 4-20mA + HART / Profibus DP |
| Power supply | 85-255V AC / 24V DC |
| Protection class | IP67 (transmitter) |
| Display | Multi-line LCD, Chinese menu |
Common Problems and Maintenance
- Fluctuating measured value: check whether the sensor surface has scaling, clean it, and re-commission.
- No signal output: confirm that the power supply and wiring are correct, and check the fuse.
- Large error in DP version: check whether the high and low pressure side connections leak, and recalibrate the zero point.
- Regular maintenance: inspect the sensor and sealing ring every six months to ensure measurement accuracy.
Summary
With its reliability and flexibility, the FMU90 ultrasonic level transmitter has become a preferred solution for industrial level measurement. Correct installation, setup, and maintenance are the keys to ensuring long-term stable operation. For complete operating details, please download the FMU90 Chinese Manual DP Version above.