Levelflex 1GHz Guided Wave Radar Level Transmitter Overview
The Levelflex series 1GHz guided wave radar is a level measurement instrument specifically designed for complex industrial conditions. It uses guided wave radar technology to detect the material surface through high-frequency pulses propagating along a probe rod or cable, achieving continuous, high-precision level measurement. Compared with traditional radar, 1GHz guided wave radar performs more stably in harsh environments such as dust, steam, and foam.
This series of instruments is widely used in chemical, petrochemical, water treatment, food and pharmaceutical industries, and is especially suitable for measuring liquids, slurries, granular solids, and interfaces. Its core advantage lies in the strong penetration and anti-interference ability brought by the low frequency of 1GHz, while the guided wave structure ensures concentrated signal energy and stable, reliable echoes.
Working Principle and Technical Features
Guided Wave Radar Measurement Principle
Guided wave radar works based on the time-domain reflectometry (TDR) principle. The instrument emits low-energy microwave pulses that propagate downward along a metal probe rod or cable. When the pulse encounters the material surface, due to the sudden change in dielectric constant, part of the energy is reflected back to the instrument. By measuring the time difference between the transmitted and received pulses and combining it with the speed of light, the instrument calculates the material distance.
Because the microwave pulse propagates along the guided wave structure, the energy is concentrated and is not affected by obstacles inside the vessel, so measurement accuracy is high and the dead zone is small. The longer wavelength of the 1GHz frequency provides stronger penetration through steam, dust, and foam, making it suitable for harsh working conditions.
Core Performance Advantages
- High precision and repeatability: measurement accuracy up to ±2mm, repeatability better than 1mm.
- Strong anti-interference ability: the 1GHz low-frequency signal can penetrate steam, dust, and foam and is not affected by changes in dielectric constant.
- Wide measurement range: range up to 30 meters (cable type), meeting the needs of large storage tanks.
- Multiple process connections: threaded, flanged, and sanitary connections, adapting to different installation requirements.
- High temperature and pressure resistance: process temperature up to 400°C, pressure up to 40bar.
- Intrinsic safety and explosion protection: optional Ex ia IIC T6 Ga explosion-proof certification, suitable for hazardous areas.
Selection Parameters and Comparison
Key Technical Parameters
| Parameter | Rod type | Cable type | Coaxial type |
|---|---|---|---|
| Range | Max 6 m | Max 30 m | Max 6 m |
| Process temperature | -40~200°C | -40~200°C | -40~400°C |
| Process pressure | -1~40bar | -1~40bar | -1~40bar |
| Accuracy | ±2mm | ±5mm | ±2mm |
| Applicable media | Liquids, slurries | Liquids, solid particles | Low dielectric constant liquids |
Selection Key Points
- Medium dielectric constant: when the dielectric constant is below 2, coaxial or cable type is recommended.
- Installation space: rod type is suitable for small tanks, cable type for tall tanks, and coaxial type for precision measurement.
- Process conditions: for high-temperature and high-pressure conditions, coaxial type or rod type with ceramic seal is preferred.
- Explosion-proof requirements: for hazardous areas, intrinsically safe or flameproof type must be selected.
- Output signal: 4-20mA/HART, Profibus PA, Foundation Fieldbus are optional.
Installation and Commissioning Guide
Installation Precautions
- Avoid installation at the feed inlet: prevent material impact on the probe rod causing false echoes.
- Keep distance between probe rod and tank wall: recommended greater than 100mm to reduce tank wall interference.
- Cable type needs to be fixed: the bottom should be fixed to prevent swinging.
- Coaxial type needs to be vertical: ensure the probe rod is perpendicular to the material surface.
- Reliable grounding: the instrument housing must be well grounded to ensure stable measurement.
Commissioning Steps
- After power-on, connect to the instrument via HART handheld communicator or host computer.
- Set the empty tank calibration (E point) and full tank calibration (F point).
- Adjust the dielectric constant and echo threshold according to the medium characteristics.
- Enable the false echo suppression function and store the interference curve.
- Verify the correspondence between output current and level to complete commissioning.
Typical Applications and Common Questions
Application Scenarios
- Chemical storage tanks: measure liquid levels of acid-base solutions, solvents, etc.
- Water treatment: sludge-water interface measurement in sewage tanks and sedimentation tanks.
- Food and pharmaceutical: sanitary connections, measuring syrup, milk, etc.
- Solid silos: level measurement of granules and powders, such as plastic pellets and cement.
- Oil and gas industry: liquid levels in hazardous areas such as crude oil and liquefied gas.
Common Questions and Answers
- Q: What should I do if the measured value fluctuates?
A: Check whether the probe rod is scaled, whether the grounding is good, and re-suppress false echoes. - Q: Inaccurate measurement of low dielectric constant media?
A: Choose a coaxial probe or increase the probe rod length to improve signal strength. - Q: Weak signal in steam environment?
A: 1GHz guided wave radar itself is resistant to steam. If it is still weak, appropriately reduce the transmission power or choose a higher frequency. - Q: No output from the instrument?
A: Check the power supply, fuse, and wiring, and confirm whether HART communication is normal.
For more product details or selection support, please watch the video introduction below: