Overview of Servo Level Gauge NMS81
Servo level gauge NMS81 is a high-precision intelligent level measuring instrument, widely used in tank level monitoring in petroleum, chemical, storage and transportation industries. The instrument is based on a servo motor driving a float to track liquid level changes, featuring high measurement accuracy, good stability, and strong anti-interference ability. This article, combined with the NMS81 Chinese manual, systematically introduces its technical parameters, installation and commissioning, and selection points.
Download NMS81 Chinese Manual.pdf to obtain the complete operation guide and safety notices.
NMS81 Servo Level Gauge Working Principle and Core Advantages
Working Principle
NMS81 adopts the servo balance measurement principle: the float is connected to the servo motor through a measuring wire. The motor adjusts the tension in real time according to the float position change, so that the float always follows the liquid level. The level change is converted into an electrical signal output by the encoder, achieving continuous and precise measurement.
Core Advantages
- High precision: measurement accuracy up to ±1mm, meeting trade settlement-level requirements.
- Multi-parameter measurement: can simultaneously measure level, interface, and density (optional).
- Strong environmental adaptability: suitable for harsh working conditions such as high temperature, high pressure, and corrosive media.
- Long-term stability: the servo drive system has little wear and a long maintenance cycle.
NMS81 Main Technical Parameters
The following parameters are excerpted from the NMS81 Chinese manual for selection reference.
| Parameter Item | Specification |
|---|---|
| Measuring range | 0~40m (customizable) |
| Measurement accuracy | ±1mm |
| Resolution | 0.1mm |
| Power supply | 24V DC or 220V AC |
| Output signal | 4~20mA / HART / RS485 Modbus |
| Process temperature | -40℃~+200℃ |
| Process pressure | 0~4MPa |
| Protection class | IP67 (optional IP68) |
| Explosion-proof grade | Exd IIC T6 Gb |
NMS81 Installation and Commissioning Steps
Preparation Before Installation
- Confirm that the tank flange specification matches the instrument interface.
- Check whether the float and wire are intact, without bending or corrosion.
- Read the safety warnings in the NMS81 Chinese manual.
Installation Steps
- Install the instrument vertically on the top flange of the tank, ensuring the float can rise and fall freely.
- Adjust the installation position so that the float avoids the liquid inlet and agitator.
- Connect the power and signal cables, paying attention to single-end grounding of the shielding layer.
- After power-on, enter the commissioning menu and set the upper and lower level limits and medium density.
- Perform automatic calibration and observe whether the float tracking is stable.
Commissioning Precautions
- Avoid friction between the wire and the tank wall; install a guide pipe if necessary.
- For first commissioning, fill liquid slowly to prevent violent fluctuation of the float.
- Regularly check wire tension and float cleanliness.
NMS81 Selection and Procurement Points
When purchasing the servo level gauge NMS81, the following information must be confirmed according to working conditions to ensure instrument applicability.
| Selection Element | Description |
|---|---|
| Measuring medium | Corrosive media require anti-corrosion materials (such as 316L, Hastelloy) |
| Process temperature/pressure | Beyond the standard range requires custom high-temperature and high-pressure models |
| Explosion-proof requirements | Explosive environments must choose explosion-proof models |
| Output signal | Choose 4~20mA, HART, or Modbus according to the control system |
| Installation method | Flange specification and installation height must match the tank |
It is recommended to request the NMS81 Chinese manual and explosion-proof certificate from the supplier, and confirm after-sales calibration service.
Common Problems and Maintenance Recommendations
Common Problems
- Level fluctuation: check whether the float is stuck and whether the wire is loose.
- Measurement deviation: recalibrate the zero point and confirm the medium density setting is correct.
- No output signal: check the power supply, wiring, and fuse.
Maintenance Recommendations
- Check wire wear and float corrosion every 6 months.
- Perform accuracy calibration once a year and record calibration data.
- Clean the instrument housing to maintain good heat dissipation.
Conclusion
With its high precision and multi-parameter measurement capability, the servo level gauge NMS81 has become an ideal choice for tank level monitoring. Correct selection, standardized installation, and regular maintenance are the keys to ensuring its long-term stable operation. For detailed operating instructions, please download the NMS81 Chinese Manual.pdf.