Purpose, Classification And Composition Of Radar Level Meter

- Dec 21, 2017 -


Radar level meter

Radar level meter using microwave pulse measurement method, and in the industrial frequency band range of normal beam energy is low, can be installed in a variety of metals, non-metallic containers or pipes, the liquid, slurry and granular material level Non-contact continuous measurement. For dust, temperature, pressure changes, there are occasions of inert gas and steam. Radar level meter on the human body and the environment without any harm, but also has no media by the proportion of the impact of dielectric constant changes from the impact of the school does not require on-site adjustment, etc., both for industrial needs, or for customers affordable Consider, are a good choice.


Radar level meter classification

Radar level gauge has become the mainstream products in the level measuring instruments market, mainly divided into radar level gauge and guided wave radar level gauge.

Very short microwaves with very low transmit power are transmitted and received by the antenna system. Radar waves operate at the speed of light. Running time can be converted into level signals by electronic components. A special way to extend the time to ensure a very short period of time stable and accurate measurements. Even with false reflections, the latest micro-processing techniques and software can accurately analyze the echos. By entering the container size, the overlying distance value can be converted into a signal proportional to the level. Instrument can be short positions debugging. The application of solid measurements can use K-band high-frequency sensors. Due to the very good focusing of the signal, the mounting or silo adhesive in the silo does not affect the measurement.

Guided wave radar level gauge

The microwave pulses from the guided wave radar level gauge run along a cable, rod, or coaxial sleeve containing a rod. Upon contact with the measured medium, the microwave pulse is reflected back and received by the electronics and analyzed Its run time. The microprocessor recognizes the echoes of the echoes and, after analysis and calculation, translates them into level signals. As the measurement principle is simple, you can not adjust with the material, thus saving a lot of debugging costs. Cables or rods can be truncated to make them more suitable for on-site applications. Not sensitive to steam, even in the smoke, noise, steam is very strong, the measurement accuracy is not affected. Unaffected by changes in the characteristics of the medium, the density of the measured medium or dielectric constant changes will not affect the measurement accuracy. Adhesion: No problem, adhering media to the measuring probe or container wall does not affect the measurement results. Containers within the container if the use of coaxial sleeve-type measurement is completely unaffected by the installation of the container, does not require special debugging. Different types of probes are available for different applications: Cable, for measuring liquid or heavy solid media up to 60 meters range; Bar for measuring liquid or light-weight solid media up to range 6 m; Coaxial sleeve for measuring low-viscosity media, independent of process conditions, measuring range up to 6 m.

working principle

The microwave level gauge works like a radar: emits microwaves to the target under test, and the echo returned by the target returns to the transmitter to be received, compared with the transmitted waves to determine the presence of the target and calculate the distance from the emitter to the target.


Instrument part

z ambient temperature: -20-60 ℃

z Power supply: AC 220V ± 10% 50Hz

z measurement accuracy: 0.5% power consumption: ≤ 3W

z Analog output: 4-20mA, load capacity ≤ 550Ω

z relay output: 4 relay switching contacts (AC 220V 2A)

z Installation: pan opening 152 (W) × 76 (H) Wall Size 210 (W) × 280 (L) × 110 (Thick)

Probe part

z medium temperature: -40-240 ℃

z Transmission distance: The signal transmission distance between sensor and instrument is less than 1.2km

z Probe types: rod, cable, coaxial, heavy cable

z installation size: G1.5 pipe thread

z warehouse pressure: less than 4MPa

LD-DLE-type universal capacitance level gauge

The realization of the capacitive level meter feed a simple operation to complete the calibration; so as to achieve the perfect combination of strong function and easy operation of level measurement, fully reflects our innovation and ability to advance with the times. It consists of sensors and secondary instrument composed of two parts. The sensor is placed on top of the silo, the probe extends vertically into the silo, and the secondary instrument is placed at other suitable places. Sensor changes the level of change into the corresponding electrical pulse signal, as far as the secondary instrument processing, and then the light bar display level, and high / low limit alarm and 4 ~ 20mA transmitter output for liquid / Solid material crop height display, alarm, control and remote display or composition of the system.

Working power: AC220V ± 10% or DC24V

Power consumption: 5W Display mode: Bargraph display

Measurement accuracy: ≤ ± 1% F · S

Sensor protection rating: IP65

Instrument working environment temperature: -40 ~ 45 ℃

Probe work (medium) temperature: Normal type: -20 ~ 60 ℃

Medium temperature type: -40 ~ 200 ℃ High temperature type: -40 ~ 800 ℃

Medium pressure: pressure ≤ 3MPa (the remaining models for atmospheric pressure)

Sensor and secondary instrument connection and distance: distance <200m, with diameter

1.5mm above the wire (preferably twisted pair) connection, each wire resistance should be

Less than 3 ohms

Detection range: ≤ 11000p

Alarm output: Two sets of relays normally open, normally closed contacts, corresponding to high and low two output, respectively, optional 90%, 80%, 70% and 30%, 20%, 10%, the factory is set At 80% and 20%. (Contact capacity AC250V, 0.3A; DC28V, 0.5A; resistive load)

Transmit output: 4 ~ 20mA

Secondary instrument Overall dimensions: 48 (W) × 96 (H) × 112 (D)

Secondary instrument hole size: 43 +1 (W) × 91 +1 (H)

Application areas

Nowadays, people in the field of level measurement have trouble measuring the level of some large solid silos, especially for dusty and turbulent loading silos up to 50/100 meters. Related art instruments, such as capacitors or guided wave radar TDRs, are subject to high tensile loads as they drop during discharge, which can damage the meter or collapse the roof. Hammers often have the problem of burrs, requiring frequent maintenance, as are most other mechanical gauges. High-dust conditions in turn may exceed the capabilities of non-contact ultrasonic level measurement systems.

High-frequency FM radar technology is particularly suitable for this large solid silos level measurement!

Today's high-frequency radars are generally radar level gauges working in the K band (24-26 GHz). The higher the operating frequency of the radar, the shorter the electromagnetic wavelength, the easier it is to reflect on tilted solid surfaces, Narrow beam width, can effectively avoid obstacles, high frequency radar can also use a smaller antenna. The FMCW FM continuous wave microwave level transmitter emission and reception signals are at the same time, the same time the microwave signal emitted more solid measurement can reduce the high dust solid silos measurement of wave phenomenon. Therefore, the high-frequency FM radar in solid measurement can provide accurate and reliable measurement and is also well used in such media as PP powder and PE powder in the chemical industry. However, due to technical limitations, there is currently no HF radar level gauge operating above the K band.

But also use the low frequency radar 5.8GHz ~ 10GHz to measure the solid, but because of its lower frequency, longer wavelength of the transmitted wave is not easy to be diffuse reflection, in high dust conditions will lead to many secondary or multiple echoes, Interference and noise are large, so the solid powder measurement is gradually eliminated.


Related News