Radar level measurement technology is mainly divided into two types: Guided Wave Radar and Non-Contact Radar. While both use microwave signals to measure level, their working principles and applications differ significantly.
1. Working Principle
Guided Wave Radar:
GWR transmits microwave pulses along a probe (rod, cable, or coaxial) that is in direct contact with the medium. The signal travels down the probe and reflects back when it reaches the surface of the material. The level is calculated based on the time-of-flight of the reflected signal.
Non-Contact Radar:
Non-contact radar emits microwave signals through an antenna into free space. The signal reflects off the material surface and returns to the antenna. The level is determined by measuring the time delay between transmission and reception.
2. Installation Method
GWR: Requires insertion of a probe into the tank → contact measurement
Non-contact radar: Installed on top of the tank → no contact with medium
3. Application Suitability
Guided Wave Radar:
Small to medium tanks
Stable surfaces
Liquids with low dielectric constant
Interface measurement (e.g., oil & water layers)
Less affected by foam, vapor, or turbulence
Non-Contact Radar:
Large tanks or silos
Corrosive, hazardous, or high-temperature media
Situations where contact must be avoided
Bulk solids (powder, grain)
Complex tank structures (with proper configuration)
4. Accuracy and Stability
GWR: Generally more stable and reliable in difficult conditions due to guided signal
Non-contact radar: High accuracy (especially 80GHz), but may be affected by dust, foam, or obstructions
5. Maintenance and Durability
GWR: Probe is in contact with the medium → may experience coating, corrosion, or buildup
Non-contact radar: No contact → lower maintenance, longer service life
6. Measurement Range
GWR: Typically up to 30 meters
Non-contact radar: Can reach 70–120 meters, depending on frequency
7. Cost Consideration
GWR: Usually more cost-effective for smaller tanks
Non-contact radar: Higher initial cost, especially for high-frequency (80GHz) models
8. Key Comparison Summary
Feature Guided Wave Radar (GWR) Non-Contact Radar
Contact with medium Yes No
Installation Probe inserted Top-mounted
Best for Liquids, interface Liquids & solids
Resistance to foam/vapor Strong Moderate
Maintenance Medium Low
Max range ~30 m Up to 120 m
Choose Guided Wave Radar when you need high stability, interface measurement, or reliable performance in foam/vapor conditions.
Choose Non-Contact Radar when you require non-invasive measurement, long distance, or handling of corrosive and hazardous media.
Post time: Apr-03-2026