RF Admittance Level Sensor

RF Admittance Level Sensor is developed from radio frequency capacitance. More accurate and more applicable continuous level measurement.

Features of RF Admittance Level Sensor

The radio frequency admittance level meter has the following advantages:

• Anti-hanging material: unique independent measurement impedance and capacitive reactance design improve the anti-hanging ability
• Strong adaptability: Probe temperature range: -100 ℃…500 ℃
• Range: The minimum measurement range can reach a few centimeters and the maximum measurement range can reach hundreds of meters
• Interface measurement: suitable for measuring oil-water interface and gas-liquid interface
• Non-sticky: suitable for measuring viscous materials, the probe has no hanging material
• High stability: stable and reliable output, resistant to fly ash, blanking, moisture, crystallization, waxing
• Maintenance-free: no movement, no wear parts, no need for frequent cleaning, maintenance, and debugging 　　
• Better measurement effect for materials such as powder particles;
• The process connection size is small, which is convenient for hole installation;
• It has better adaptability to the measurement of small tanks and special tanks;
• The measurement blind area is small, which maximizes the measurement range;
• Good directionality, especially special tanks and special-shaped tanks, with low transmission loss and many measurable media.

RF Admittance Level Sensor Probe Types

Specifications of RF Admittance Level Sensor

Power supply:	13VDC～35VDC
Output:	4～20mA
Environment temperature:	-40℃～70℃
Medium temperature:	-100℃～800℃
Linearity:	0.50%
Repeatability:	0.10%
Delay:	1～30s adjustable
Spark protection:	built-in spark protection circuit (to sensor)
Electrical interface:	M20*1.5
Cable:	The special connection cable between the split electronic unit and the sensor is standard 5m, the longest is 50m
Process connection:	BSPT threaded installation (standard)/flange installation (optional)
Shell protection:	IP66
Certification:	ExiaIICT4

Read more about: Factors To Consider When Selecting A Capacitive Level Sensor

RF Admittance Level Sensor’s Applications

1. Power plants: coal piles, raw coal bins, fuel bins, reservoirs, exhaust gas purification tanks, bin pumps, ash storage, fuel tanks, etc.
2. Chemical industry: distillation tower, raw material and intermediate silo, reaction tank, ammonia tank, toxic liquid tank, solid silo, separator, etc.
3. Petrochemical: oil pipelines, distillation towers, concentration tanks, liquefied gas tanks, ammonia tanks, steam drums, oil refinery oil depots, electrical desorption interfaces, asphalt tanks, etc.
4. Water and water treatment: reservoirs, sewage tanks, water treatment tanks, sedimentation tanks, digestion towers, gas pipelines, deep wells, drinking water networks, etc.
5. Cement: Stone silos, raw meal silos, cement silos, coal powder silos, slag storage silos, etc.
6. Metallurgy: ore silo, ore crusher, raw material silo, auxiliary silo, blast furnace, alumina powder silo, electrolytic cell buffer tank, etc.
7. Oilfield: crude oil or product oil storage tanks, three-phase separators, sedimentation tanks, sewage tanks (pools) and oil-water interfaces, drilling mud tanks, etc.
8. Papermaking: raw material warehouse, storage tower, drying drum, etc.
9. Others: quarry, food, pharmaceutical, environmental protection, shipbuilding and other industries

Extended reading: GWR Solid Level Sensor-for Cement silo-Ash powder measure

RF Admittance Level Sensor Working Principle

RF Admittance Level Sensor works based on radio frequency admittance level control technology. Radio frequency admittance level control technology is a development from capacitive level control technology. The material to which the sensor adheres is called hanging material. The anti-hanging material performance is better, the work is more reliable, and the measurement is more accurate. Level control technology with wider applicability. The meaning of “admittance” in “radio frequency admittance” is the reciprocal of impedance in electricity. It is composed of resistive, capacitive and perceptual components. “Radio frequency” means high frequency, so radio frequency admittance technology can be understood as a method of measuring admittance with high frequency current.

The important difference between point radio frequency admittance technology and capacitance technology is the use of three-terminal technology and the diversity of measurement parameters. The measurement signal at the center end of the circuit unit is connected with the center line of the coaxial cable. Then connect to the center end of the sensor.

At the same time, the shielding layer of the coaxial cable is suspended on a level that is very small and very stable, but has the same potential, the same phase and the same frequency as the measurement signal, but has no direct electrical relationship, that is, isolated from each other. The effect is equivalent to that the measured signal passes through a non-inverting amplifier with a gain of “1” and a strong drive capability. The output is connected to the shield of the coaxial cable. Then connect to the shielding layer of the sensor. The ground wire is another independent wire in the cable.

Because of the above-mentioned relationship between the center line of the coaxial cable and the outer shield, there is no potential difference between the two. Therefore, no current flows, that is, no current leaks from the center line. It is equivalent to no capacitance between the two or the capacitance is equal to zero. Therefore, the temperature effect of the cable and the installation of capacitors will not have an impact.

For the problem of hanging material on the sensor. Adopt a new sensor structure, five-layer concentric structure.

Sensor structure: The innermost layer is the center probe, the middle is the shielding layer, and the outermost is the grounded mounting thread, which is isolated by an insulating layer. As with the coaxial cable, there is no potential difference between the center probe and the shield. Even if the impedance of the hanging material on the sensor is small, no current will flow.

The electronic instrument measures only the current from the center of the sensor to the opposite tank wall (ground). Because the shielding layer can prevent the current from flowing back along the sensor to the container wall. Therefore, the ground current can only pass through the measured material to the opposite container wall through the end of the sensor.

That is, U center probe = U shielding layer, I center probe pair shielding layer = (U center probe-U shielding layer) × YL=0.

Although there is a potential difference between the shielding layer and the container wall, current flows between the two. But the current is not measured and does not affect the measurement result. In this way, the measuring terminal is protected from the influence of hanging materials. Only when the material in the container actually opens up and contacts the central probe, the measured current can be formed between the central probe and the ground through the measured material. The instrument detects this current and generates an effective output signal.

Radio frequency admittance technology introduces measurement parameters other than capacitance, especially resistance parameters. The signal-to-noise ratio of the radio frequency admittance level meter measurement signal increases. The resolution, accuracy and reliability of the radio frequency admittance level gauge are greatly improved. The diversity of measurement parameters also greatly expands the reliable application fields of radio frequency admittance level gauges.

The radio frequency admittance level gauge sensor can choose a variety of materials. Can be installed integrally or separately. Used for limit control and alarm. Welcome to contact Sino-Inst for detailed information.

Extended reading: GWR Solid Level Sensor-Cement silo-Ash powder measure

Application Range of Various Level Sensors

There are many types of level gauges. There are heavy hammer level gauges, resistance-rotation level gauges, radio frequency admittance level gauges, diaphragm level gauges, tuning fork level gauges, vibrating rod level gauges.

They each have their own advantages and are suitable for different working conditions.

Rotary resistance level gauge

The anti-rotation level gauge can be used for the measurement of solid particles and dust. Mainly used in feed, silica, stones, spherical particles, wood chips, calcium powder, rubber, metal, limestone, grain, foundry sand, sawdust, coal powder, resin, raw leather, peanuts, clay and other materials measuring.

Radio frequency admittance level gauge

RF admittance level gauge products are widely used. Several typical occasions are as follows: the measurement of materials such as chemicals, plastics, films, feed, grain rubber medicines, liquid waste water, sand, food slurry cement, powder coating/clothing coal, granular solid oil and paper pulp.

Diaphragm level gauge

The diaphragm level gauge can be installed outside the container, whether it is installation, maintenance, equipment replacement or sensitivity adjustment. In practical applications, it is not recommended to use in the environment where the material is extremely light, viscous or large particles

Tuning fork level gauge

A dual-purpose level switch with an intelligent circuit for the tuning fork level gauge. Suitable for almost all liquids, light, easy-flowing solids

Vibrating rod level gauge

The vibrating rod level gauge can be used to monitor powder, grain or bulk materials (the diameter does not exceed 5-10cm). The density of the material must be greater than 0.05KG/DM3.

If it is lower than this density, the internal friction of the material will not be enough to weaken the amplitude of the vibration switch. This kind of vibrating level switch can be widely used in the monitoring of coal, cement, limestone, grain, sugar, fly powder and other materials.

Featured Level Sensors

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Sino-Inst offers over 10 RF Admittance Level Sensors for level measurement. About 50% of these are RF level meters, 40% is the tank level sensor.

A wide variety of RF Admittance Level Sensors are available to you, such as free samples, paid samples.

Sino-Inst is a globally recognized supplier and manufacturer of RF Admittance Level Sensor instrumentation, located in China.