What Are Principle and Difference Between Radar Level Meter and Guided Radar Level Meter

Radar Level Transmitters

Radar Level Meter


Transmission-reflection-reception is the basic working principle of radar level meter.

The antenna of the radar sensor transmits electromagnetic wave signals in the form of a beam. The transmitted wave is reflected off the surface of the measured material, and the reflected return signal is then received by the antenna.

Each point in the transmitted and reflected beam is collected using ultrasonic sampling. The signal is processed by the intelligent processor to derive the distance between the medium and the probe, and sent to the terminal display for display, alarm, operation and so on.

26G Non-contact radar level transmitter


The biggest feature of the radar level meter is that it has remarkable efficacy under adverse conditions. Whether it is toxic media, or corrosive media, and whether it is solid, liquid or dusty, slurry media, it can be measured. In terms of measurement, it has the following characteristics:

  • Continuous and accurate measurement

The probe of the radar level meter has no contact with the surface of the medium, which is a non-contact measurement, and can accurately and quickly measure different media. The probe is almost unaffected by temperature, pressure, gas, etc.(the effect is only 0.018% at 500℃ and 0.8% at 50bar).

  • It has suppression function for interference echo
  • Accurate and safe energy saving

Radar level gauge materials used in the chemical and mechanical properties are quite stable, and materials can be recycled, very environmentally friendly.

  • No maintenance and high reliability

Microwaves are virtually non-interfering, requiring no direct contact with the measurement medium. They can be utilized in almost all kinds of applications, such as vacuum measurement, liquid level measurement, or material level measurement. Due to the use of advanced materials that are highly durable under complex chemical and physical conditions, microwaves provide accurate, reliable, and long-term stable analog or digital level signals.

  • Easy maintenance and simple operation

Radar level meter has fault alarm and self-diagnosis function. According to the error code prompted by the display module’s operation, analyze the fault to determine it promptly for elimination. This ensures that maintenance and correction are more convenient and accurate, thereby guaranteeing the normal operation of the instrument.

  • A wide range of applications, almost all media can be measured

From the shape of the tank body, the radar level meter can measure the level of spherical tanks, horizontal tanks, cylindrical tanks, cylindrical vertebrae tanks, etc.; from the tank function, you can measure the level of storage tanks, buffer tanks, microwave tubes, by-pass tubes in the tanks; from the measured medium, you can measure the level of liquids, particles, slurries and so on.


In a nutshell, it is a radar level meter with a wide range of use and a non-contact measurement method. Excellent material, low failure rate.

Guided Wave Radar Level Meter


Guided wave radar level meter is based on the principle of time-traveling measurement. The instrument utilizes radar waves that travel at the speed of light, and the time taken for these waves to travel can be converted into a level signal through electronic components. The probe emits high-frequency pulses that propagate along the cable probe. When these pulses encounter the material surface, they are reflected back and received by the receiver inside the instrument. The distance signal is then converted into the level signal.

Guided wave radar level transmitter


  • Strong inhibition of vapour and foam, measurement is not affected;
  • It is not affected by the density of liquid, the loose degree of solid materials, temperature, dust when adding materials;
  • Low-cost maintenance, high performance, high accuracy, high reliability and long service life.

What’s the Difference?


Different contact mode.

Radar level meter is non-contact, guide wave level meter is contact. That is to say, in the food grade requires high occasions, can not use the pilot type.

The use of different working conditions.

Guided-wave radar level meters need to consider the corrosion, viscosity of the medium, and adhesion. Additionally, excessively long installations of guided-wave radar make maintenance more difficult. In conditions of low dielectric constant, both radar and guided-wave radar measurements rely on the difference in dielectric constants of the medium. The wave emitted by ordinary radar is dispersive; hence, when the dielectric constant of the medium is too low, the signal becomes too weak and unstable to measure. In contrast, guided-wave radar propagates along the guided-wave rod, resulting in a relatively stable signal. Moreover, general guided-wave radar units typically incorporate bottom detection functionality, enabling correction of the measurement values based on signals returned from the bottom. This feature enhances signal stability and accuracy.

Selection is different.

Ordinary radar can be used interchangeably with guided-wave radar, but due to the fixed length of the guided-wave rod (cable) according to the original conditions, generally, they are not compatible for use. Due to this, the selection of guided wave radar is more troublesome than ordinary radar.

Different measurement range.

Radar level meter more measuring 30.40m tank, even can measure up to 60m. Guided-wave radar also needs to consider the situation of the guided-wave rod (cable) under force, and due to the general use of guided-wave radar for measurement, the distance covered is not usually very long. However, in certain special conditions, guided-wave radar has obvious advantages. For instance, in tanks where stirring occurs or where there are media fluctuations, guided-wave radar demonstrates greater stability in measurement values compared to flux radar. Additionally, in small tanks where level measurement is required, conventional radar is often not applicable due to limited installation space or increased interference within the tanks. It is in such scenarios that the advantages of guided-wave radar become evident.

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