Multi functional RF admittance level meter

The multifunctional control RF admittance level switch is a level switch instrument based on the principle of RF capacitance measurement.

As the height of the material in the container changes, the capacitance also changes, which can be detected by microcontrollers and electronic circuits. When the level reaches the alarm point set by the user, the relay inside the instrument will turn on or off. This switch is a digital intelligent instrument that uses a digital tube to display the measured capacitance value in real time, and can automatically set the alarm point and hysteresis by long pressing a single key, simplifying the operation of on-site personnel.

Provide multiple alarm output methods for easy on-site integration. This includes single point alarm (DPDT), dual point alarm (2 SPDTs), and two-point control (liquid level control, DPDT). It can also be used with two probes to provide an independent alarm point for each probe.

2 Working principle

The product uses the oscillation circuit method to measure the capacitance between the probe and the container wall. The probe tank wall capacitance and internal circuit form an improved Colpitts oscillation circuit. When the height of the medium changes, the capacitance changes accordingly, causing a change in the oscillation frequency. This frequency signal is collected by the microcontroller and converted into a capacitance value display. At the same time, the microcontroller will set the relay output based on the measured capacitance value and the set alarm point. Compared with other capacitance measurement methods, the oscillation circuit method has more stable measurement values, is less susceptible to electromagnetic interference, and has a faster response time.

3 Product Features

● High reliability

● High sensitivity (0.1pf)

● Low maintenance cost

Multiple alarm methods for users to choose from

Widely applicable media: It can detect conductive and non-conductive media, various liquids, solid particles, powders, and slurries.

Probe material: 316SS, Telfon, ceramic, Kynar (heat-resistant and wear-resistant alloy)

Can withstand medium temperatures up to 800 ℃ (ceramic probe)

● Withstand voltage up to 10Mpa

● Can overcome the influence of probe adhesion and hanging materials on measurement

● Alarm points can be set by long pressing a single key (one key setting)

4 Technical parameters

5 Product Installation

(1) The probe should be installed vertically from the top of the container. Do not allow the probe to directly contact the container wall or bottom, except for the process connection components.

(2) Ensure that the probe is inserted and secured without touching any obstacles in the container, such as the mixing mechanism. The probe should be installed away from the feed inlet to avoid splashing interference.

(3) When installing probes with insulation coating, careful attention should be paid to prevent damage to the insulation coating.

(4) For pressure vessels, flange or threaded process connections can be sealed with glue to prevent leakage.

(5) When tightening the threaded connection, do not directly rotate the instrument housing, but use a suitable wrench to rotate the fastening part.

(6) In situations with significant interference, it is necessary to ensure reliable grounding of the system.

(7) When the tank wall is non-metallic, a double pole probe must be used, and the ground terminal of the shell should be connected to the nearest ground (such as a metal structure, etc.).