product overview

The UDM-20 series floating ball liquid level transmitter is suitable for industrial and civil building water towers, water tanks, collection pits, and industrial wastewater treatment departments. Widely used in sectors such as refining, chemical, metallurgical, power, papermaking, food, and industrial wastewater treatment.

This series can adapt to various liquid media: conductive and non-conductive liquid levels such as water, oil, alkali, acid, sewage, etc. False liquid level suspended solids have no effect on measurement. Explosion proof and safety transmitters can also be used in explosive environments.

This series of products has a simple structure, easy installation, and reliable operation. It can display on-site and output standard current signals, with a transmission distance of up to 2 kilometers. Equipped with our company's XMT series universal display meter, it can achieve three wire and two wire connections. The display instrument has three types: pointer type, digital type, and light column type. The latter two can simultaneously display the percentage height and absolute value height of the liquid level. It has upper and lower limits, upper and lower limits, relay contact signal output, and is used for dangerous liquid level alarm, inspection, and control. It is highly welcomed by users and design units.

Technical parameter indicators

1. Measurement range 0‐ 0.5m~0— 6m (static pressure type is suitable for 4m and above)

2. Transmitter accuracy&plusmn; 1.5% (H&ge; 1.0m)&plusmn; 2.5% (when H<1m)

3. Measure medium temperature -20~125 ℃

4. Measure medium pressure from 0 to 600Kpa (special orders not exceeding 2.5MPa)

5. Measure the specific gravity of the medium:& Ge; 0.68 viscosity&le; 0.05Pa&middot; S

6. Environmental conditions for use: temperature -10~55 ℃, humidity&le; 95%, no strong vibration.

7. Load resistance 8, explosion-proof features: explosion-proof type dIIBT4, intrinsic safety type IIACT4.

Working principle

The UDM-20 series floating ball liquid level transmitter consists of a magnetic floating ball, measuring conduit, signal unit, electronic unit, junction box, and installation components.

Magnetic float with a specific gravity less than 0.5 can float above the liquid surface and move along the measuring tube. The measuring element is installed inside the conduit, which generates a resistance signal proportional to the liquid level change under the action of an external magnetic field. The strong electronic unit converts it into a 4&mdash; 20mA or other standard signal output. In the process design, the electronic unit adopts module circuits from Daming Company, which are moisture-proof, earthquake resistant, and resistant to acid and mold corrosion. The circuit is equipped with a constant current feedback circuit, and the power supply voltage is 14V; 45V variation or load resistance 0&dash; When changing at 750 ohms (4&mdash; 20mA), the error should not exceed 0.5%. When the internal protection circuit fails, the maximum output current should not exceed 28mA to reliably protect the power supply and secondary meter from damage.

Installation precautions

When installing the controller, attention should be paid to avoiding bending and shaking to prevent damage to the internal signal points. Especially when it is longer, attention should be paid. If it exceeds 4m for transportation convenience, the user needs to assemble it on site; First, connect the guide rods and use instant adhesive to bond them together. Then, fix the signal core in place. After inspection, it can only be installed if everything is normal

The PTFE plastic coating is designed to prevent corrosion, so be careful during installation. Do not scratch the PTFE to avoid losing its anti-corrosion effect.

Wiring of float level gauge transmitter in system measurement

The UDM-20 series transmitter has a wide range of compatibility and can be connected to various secondary instruments that receive current and voltage signals. The application is shown in Figure 4 and Figure 5

Pairing a two-wire transmitter with an XDM-10 liquid level indicator controller can save the need for an external 24V power supply

On site installation of float level gauge transmitter

1. The transmitter should be installed in a reasonable manner according to specific usage conditions, referring to the installation legend. Installation should be completed by two or more people working together. When installing longer measuring guide rods, special attention should be paid to avoiding bending and shaking to prevent damage to internal measuring components. For anti-corrosion transmitters, the PTFE coating should be protected from punctures and scratches to prevent loss of anti-corrosion applicability and shorten the service life of the instrument.

2. Explosion proof transmitters should be wired and used according to the following regulations to protect their explosion-proof performance.

3. The transmission cable from the sensor to the indicator should be a three core rubber plastic sheathed cable with a diameter of 7.5~8.5mm, and the total resistance of the wire should be ≤ 500 ohms;

4 . The cable should be laid through cable trays or protective tubes, and there should be no tension present;

5 . The wiring points should be of the terminal block type, and the corresponding wire ends and cable cutting points should be neat and intact