1. Introduction
This manual provides essential information for the safe and effective installation, operation, and maintenance of the Tbest TL-136 Submersible Liquid Level Transmitter. This high-precision sensor is designed for accurate monitoring of liquid levels in various applications. It utilizes diffused silicon technology and provides a standard 4-20mA output signal. Please read this manual thoroughly before using the product.
2. Safety Information
- Always disconnect power before performing any installation, wiring, or maintenance procedures.
- Ensure that the measured liquid does not corrode stainless steel, as this can damage the sensor.
- Handle the sensor and cable with care to prevent physical damage.
- Installation should be performed by qualified personnel familiar with electrical systems and liquid level measurement.
- Do not modify the sensor or its components.
3. Product Overview
The Tbest TL-136 Liquid Level Transmitter is a robust device featuring a stainless steel probe body and a shielded cable. It is designed for submersible applications to measure liquid levels accurately.
Figure 3.1: The Tbest TL-136 Submersible Liquid Level Transmitter with its long, coiled cable and stainless steel probe.
The sensor head incorporates multiple openings to allow liquid ingress for pressure measurement, and it is protected by an IP68 multilayer waterproof design. The cable provides electrical connection and signal transmission.
Figure 3.2: A close-up of the sensor's stainless steel probe head, showing the measurement openings and robust construction.
Figure 3.3: The sensor body connected to its cable, with the red and black wires exposed for connection.
4. Specifications
| Feature | Detail |
|---|---|
| Model Number | Tbestg2n5fgh8yv-15 |
| Measurement Range | 0-5 Meters |
| Output Signal | 4-20mA |
| Power Supply | 24VDC |
| Material | Stainless Steel |
| Protection Rating | IP68 Multilayer Waterproof |
| Probe Body Dimensions | 108mm (Length) x 28mm (Diameter) |
| Package Dimensions | 9.49 x 8.9 x 2.28 inches |
| Item Weight | 6.88 ounces |
| Manufacturer | Tbest |
5. Setup and Installation
Follow these steps for proper installation of your liquid level transmitter:
- Preparation: Ensure the power supply is off before beginning installation. Verify that the liquid in the tank or reservoir is compatible with stainless steel.
- Placement: Carefully lower the sensor into the liquid. The sensor head must be fully submerged for accurate readings. Ensure the cable is not kinked or under excessive tension.
- Wiring: Connect the sensor to a 24VDC power supply and your monitoring system (e.g., PLC, display).
- Connect the Red Wire to the positive (+) terminal of the 24VDC power supply.
- Connect the Black Wire to the negative (-) terminal of the 24VDC power supply and the signal return of your monitoring device.
- Secure Cable: Secure the air guide cable to prevent movement and ensure it remains above the liquid level.
Figure 5.1: Installation diagram illustrating the submersible sensor in a liquid tank and its physical dimensions.
6. Operating Instructions
Once properly installed and powered, the Tbest TL-136 sensor will continuously measure the liquid level and output a proportional 4-20mA current signal.
- The 4mA output corresponds to the minimum measured level (0 meters).
- The 20mA output corresponds to the maximum measured level (5 meters).
- Connect the 4-20mA output to a compatible PLC, data logger, or display unit for real-time monitoring and control.
- Ensure your receiving device is correctly configured to interpret the 4-20mA signal for the 0-5 meter range.
7. Maintenance
Regular maintenance helps ensure the longevity and accuracy of your liquid level transmitter.
- Sensor Head Cleaning: Periodically remove the sensor from the liquid and inspect the sensor head for any buildup of debris, sediment, or foreign material. Gently clean the openings with a soft brush or cloth if necessary. Avoid using abrasive materials or harsh chemicals.
- Cable Inspection: Regularly check the entire length of the cable for any signs of wear, cuts, cracks, or corrosion, especially where it enters the sensor body and where it is secured. Replace the sensor if the cable insulation is compromised.
- Connection Check: Ensure all electrical connections remain secure and free from corrosion.
8. Troubleshooting
If you encounter issues with your Tbest TL-136 Liquid Level Transmitter, refer to the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| No 4-20mA output signal. | No power, incorrect wiring, damaged cable. | Verify 24VDC power supply is active. Check wiring connections (red to +, black to -/signal return). Inspect cable for damage. |
| Inaccurate or fluctuating readings. | Debris on sensor head, air bubbles, incorrect calibration of receiving device, sensor not fully submerged. | Remove and clean sensor head. Ensure sensor is fully submerged and stable. Check calibration settings on your monitoring system. |
| Output stuck at 4mA or 20mA. | Sensor out of range (liquid level too low/high), sensor fault. | Confirm liquid level is within the 0-5 meter range. If the level is within range and the output is still stuck, the sensor may be faulty and require replacement. |
9. Warranty and Support
Tbest products are manufactured to high-quality standards. For information regarding warranty coverage, technical support, or service, please refer to the warranty documentation provided with your purchase or contact Tbest customer service directly. You may also reach out to the retailer from whom you purchased the product for assistance.
