1. Introduction
Thank you for choosing the LiebeWH Stainless Steel 4-20mA Liquid Water Level Sensor Transmitter. This device is designed for precise and reliable liquid level measurement in various industrial and environmental applications. This manual provides essential information for the safe and efficient installation, operation, and maintenance of your new sensor.
Key Applications: Water treatment plants, sewage treatment facilities, city water supply systems, high-rise building pools, wells, mines, industrial pools, water tanks, oil pools, hydrogeology, reservoirs, rivers, and oceans.
2. Safety Information
- Read all instructions carefully before installation and operation.
- Ensure power is disconnected before performing any wiring or maintenance.
- Installation should be performed by qualified personnel familiar with electrical systems and liquid level sensing equipment.
- Do not modify the sensor or cable. Unauthorized modifications may lead to malfunction or damage.
- Ensure proper grounding to prevent electrical hazards.
- Avoid exposing the sensor to corrosive liquids beyond its specified material compatibility (stainless steel).
3. Product Overview
3.1. Features
- Waterproof Cable: Equipped with a durable, long waterproof cable (approx. 33m/108.3ft) suitable for detecting water levels in the 0 to 5m range.
- Premium Material: Constructed from high-quality stainless steel for excellent anti-corrosion performance and durability, ensuring a long service life.
- High Measurement Precision: Designed for accurate readings with an anti-fouling probe that is easy to clean.
- Stable Performance: Solid structure resists bending and deformation, providing good stability and reliable operation.
- Compact Design: Facilitates easy installation and use in various environments.
- 4-20mA Output: Standard industrial output for easy integration with control systems.
3.2. Components
Figure 1: LiebeWH Liquid Level Sensor. This image shows the stainless steel sensor probe submerged in water with its long, black waterproof cable coiled beside it, illustrating its primary function.
Figure 2: Sensor Components. This detailed view highlights the IP68 protection level for anti-leakage, the stainless steel housing of the level transmitter, the polyurethane cable (33m/108.3ft) with shielded inside for anti-interference and anti-aging, and the removable anti-clogging probe at the sensor's tip.
Figure 3: Probe Design. This image illustrates the 45-degree inclination design of the sensor's pressure-inducing hole, which effectively reduces wear from impurities and allows pressure to enter smoothly, thereby reducing errors caused by liquid level fluctuations. It also shows the 3mm pressure-inducing hole, designed to be impact-resistant, anti-clogging, and offering four-hole multi-directional pressure sensing.
4. Specifications
| Parameter | Value |
|---|---|
| Manufacturer | LiebeWH |
| Model Number | LiebeWHwa8b4pdcrf3396 |
| Material | Stainless Steel |
| Cable Length | Approx. 33m / 108.3ft |
| Measurement Range | 0 - 5m (Water Level) |
| Output Signal | 4-20mA |
| Protection Level | IP68 |
| Package Dimensions | 28.9 x 28.3 x 10.4 cm |
| Item Weight | 1.86 Kilograms |
| Batteries Required | No |
5. Setup and Installation
5.1. Pre-Installation Checks
- Verify that the sensor model and specifications match your application requirements.
- Inspect the sensor and cable for any visible damage.
- Ensure the power supply for the sensor is within the specified range (typically 24V DC for 4-20mA sensors).
5.2. Mounting the Sensor
Figure 4: Installation Methods. This image displays two common methods for installing the water level transmitter: one using a flange for secure top-mounting, and another using a cable hanger for suspension. Both diagrams show the waterproof cable extending from the top and the transmitter submerged to measure the actual water level. The coiled cable on the right indicates its approximate length of 33m/108.3ft.
- Choose a Mounting Method: The sensor can be installed using a flange at the top of the tank or suspended using a cable hanger. Refer to Figure 4 for visual guidance.
- Positioning: Lower the sensor into the liquid until it reaches the desired measurement depth. Ensure the sensor probe is fully submerged and not obstructed by tank walls or other structures.
- Secure the Cable: Secure the waterproof cable at the top of the tank or conduit to prevent strain on the sensor and ensure it remains at the correct depth.
5.3. Wiring
Connect the sensor to your control system or display unit according to the wiring diagram provided with your specific control system. The sensor provides a standard 4-20mA output signal.
- Typically, two wires are used for the 4-20mA loop: one for power supply (+) and one for signal/return (-).
- Ensure correct polarity to avoid damage.
- Use appropriate cable glands and sealing to maintain the waterproof integrity of the connections, especially in humid or wet environments.
6. Operation
Once installed and wired correctly, the sensor will continuously measure the liquid level and output a corresponding 4-20mA current signal. This signal can be read by a PLC, DCS, data logger, or a dedicated display unit.
Figure 5: Liquid Level Control Diagram. This diagram illustrates a typical liquid level control system. A control unit receives a liquid level signal transmission output from the sensor. When the liquid level is low, the control unit opens the water inlet valve to add water. When the liquid level reaches the upper limit, the control unit closes the water outlet valve. The probe sinks to the bottom of the water tank to measure the level between the lower and upper limits.
- 4mA: Corresponds to the minimum measured level (e.g., empty tank or lowest point of measurement).
- 20mA: Corresponds to the maximum measured level (e.g., full tank or highest point of measurement).
- The intermediate current values linearly represent the liquid level between the minimum and maximum points.
7. Maintenance
Regular maintenance ensures the longevity and accuracy of your liquid level sensor.
- Cleaning the Probe: The sensor is designed to be anti-fouling. However, in environments with heavy sediment or viscous liquids, periodic cleaning of the sensor probe may be necessary. Gently wipe the probe with a soft cloth to remove any buildup. Do not use abrasive materials or harsh chemicals.
- Cable Inspection: Periodically inspect the entire length of the cable for any signs of wear, cuts, or damage. Ensure all cable glands and seals are intact to maintain waterproof integrity.
- Connection Check: Verify that all electrical connections are secure and free from corrosion.
- Calibration Check: If accuracy issues are suspected, verify the sensor's output against known liquid levels. Recalibration may be required for the connected control system.
8. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No output signal (0mA or open circuit) | No power, incorrect wiring, damaged cable, sensor failure. | Check power supply, verify wiring connections and polarity, inspect cable for damage, test sensor with a known good power source. |
| Incorrect or unstable readings | Probe fouled, air bubbles around probe, electrical interference, sensor not fully submerged, incorrect calibration of receiving device. | Clean sensor probe, ensure probe is fully submerged and free of bubbles, check for sources of electrical interference, verify calibration of the receiving device. |
| Output stuck at 4mA or 20mA | Sensor not detecting change, liquid level outside measurement range, sensor failure. | Ensure liquid level is within the 0-5m range, check if probe is obstructed, test sensor functionality. |
9. Warranty and Support
LiebeWH products are manufactured to high-quality standards. For specific warranty details, please refer to the terms and conditions provided at the time of purchase or contact your vendor.
For technical support, troubleshooting assistance, or inquiries about replacement parts, please visit the official LiebeWH store on Amazon or contact their customer service directly.
LiebeWH Amazon Store: Visit Store