1. Product Overview
The EARU input level/water level transmitter is engineered for precise liquid level detection. It utilizes a diffusion silicon chip, encapsulated within a stainless steel housing, with an oil-filled core. A front-end protective cap safeguards the sensor diaphragm while allowing smooth liquid contact. The wire and housing are securely sealed, and a vent pipe is integrated into the cable, connecting to the outside to prevent condensation. A built-in micro signal processing circuit enables remote transmission, ensuring excellent stability and reliability.
2. Application Range
This level sensor is versatile and widely used in various environments requiring precise liquid level monitoring. Typical applications include:
- Water plants and sewage treatment facilities
- Urban water supply systems
- High-rise building pools and wells
- Mines and industrial pools
- Water tanks and oil pools
- Hydrogeological studies
- Reservoirs, rivers, and ocean monitoring
3. Specifications
General Features:
- Fully enclosed circuit with moisture, condensation, and anti-leakage functions.
- One-piece design for enhanced durability.
- High stability and long service life.
- Fast response time (10ms, 50ms).
- Smart imported chip for reliable performance.
- Scientific/Rational Design: Features a 45° inclined opening pressure hole with a 3mm diameter.
Technical Parameters:
| Parameter | Value |
|---|---|
| Measurement Form and Range | 0～1～200mH2O (adjustable up to 300 meters) |
| Allow Overload | 2 times full scale pressure |
| Working Temperature | -20～60°C |
| Temperature Compensation | -10～60°C |
| Storage Temperature | -40～80°C |
| Output Signal | 4-20mA (default), 0-5V, 0-10V, RS485 |
| Sensor Power Supply | 10~30 VDC (Standard 24VDC) |
| Controller Power Supply | 85~260 VAC |
| Shell Material | 304 Stainless Steel (316SS diaphragm) |
| Cable | Waterproof breathable cable (Polyurethane Shielded Wire) |
| Protection Class | IP68 (Dust and splash water resistant) |
| Accuracy Level | 0.5%FS (default), 0.2%FS |
| Stable Performance | ±0.1%FS per year |
| Medium Temperature | 0-50°C |
Physical Dimensions:
The sensor has an approximate appearance size of 145mm in total length and a diameter of 28mm.
4. Setup and Installation
Package Contents:
- Level Sensor / Liquid Level Transmitter
- Cable (length varies by model, e.g., 1m range with 1m cable, 5m range with 5m cable)
- (Optional) Cable hanger or Flange for installation
Installation Methods:
The sensor can be installed using either a cable hanger or a fixed flange, depending on your application requirements.
Wiring Diagrams:
Ensure correct wiring based on the desired output signal. Refer to the diagrams below for detailed connections.
Current Output 4-20mA (2 wires): Red Cable (V+) to Power Supply (+), Black Cable (V-) to Power Supply (-) and Devices (A).
Voltage Output 0-5/0-10V (3 wires): Red Cable (V+) to Power Supply (+), Blue Cable (V-) to Power Supply (-), White Cable (Out) to Devices (A).
RS485 Output (4 wires): Red Cable (V+) to Power Supply (+), Black Cable (V-) to Power Supply (-), Blue Cable (A-) to PC (A-), White Cable (B+) to PC (B+).
5. Operating Instructions
Panel Operation:
The control panel provides real-time monitoring and configuration options.
- Display: Shows real-time water level, percentage, and alarm status.
- Set Key: Short press to enter setting mode; long press to save settings.
- Up/Down Keys: Use to adjust parameter values during setting.
- Alarm Light: A red light indicates an active alarm condition.
- Pump Light: A green light indicates that the pump is currently operating.
Operation Flow:
The system operates in a continuous loop to monitor and control liquid levels:
- Power On: Initiate the system.
- Sensor Initialization: The sensor performs a self-check.
- Display Real-time Level: The current liquid level and percentage are shown on the display.
- Check Alarm Conditions: The system continuously monitors for low and high level alarm thresholds.
- Pump Control: If the liquid level falls below the lower limit, the pump starts. If it rises above the upper limit, the pump stops.
- Loop: The system returns to displaying the real-time level and continues monitoring.
Parameter Settings:
Use the 'Set' and 'Up/Down' keys to configure the following parameters:
Primary Control Parameters:
| Parameter | Description | Range | Default |
|---|---|---|---|
| F00 | Lower limit alarm value | 0-9999 | 0 |
| F01 | Upper limit alarm value | 0-9999 | 0 |
| F02 | Lower limit pump start value | 0-9999 | 0 |
| F03 | Upper limit pump stop value | 0-9999 | 0 |
| F04 | Alarm delay time (seconds) | 0-999 | 0 |
| F05 | Pump start delay time (seconds) | 0-999 | 0 |
| F06 | Pump stop delay time (seconds) | 0-999 | 0 |
| F07 | Sensor type (0: 4-20mA, 1: 0-5V, 2: 0-10V, 3: RS485) | 0-3 | 0 |
| F08 | Full scale range (meters) | 0-9999 | 100 |
| F09 | Zero point adjustment | -9999 to 9999 | 0 |
| F10 | Full scale adjustment | -9999 to 9999 | 0 |
Secondary Internal Parameters:
| Parameter | Description | Range | Default |
|---|---|---|---|
| P00 | Display mode (0: Level, 1: Percentage) | 0-1 | 0 |
| P01 | Backlight brightness | 0-100 | 50 |
| P02 | Key lock (0: Unlock, 1: Lock) | 0-1 | 0 |
| P03 | RS485 address | 1-255 | 1 |
| P04 | RS485 baud rate (0: 2400, 1: 4800, 2: 9600, 3: 19200) | 0-3 | 2 |
| P05 | RS485 parity (0: None, 1: Even, 2: Odd) | 0-2 | 0 |
| P06 | RS485 stop bits (0: 1 bit, 1: 2 bits) | 0-1 | 0 |
| P07 | Factory reset (0: No, 1: Yes) | 0-1 | 0 |
6. Maintenance
The EARU Level Sensor is designed for low maintenance due to its fully enclosed circuit and robust IP68 protection, which guards against moisture, condensation, and leakage. To ensure optimal performance and longevity:
- Regular Inspection: Periodically check the sensor and cable for any visible signs of damage, corrosion, or wear.
- Cleaning: If used in environments with potential for buildup (e.g., algae, sediment), gently clean the sensor diaphragm to maintain accuracy. Use non-abrasive materials and avoid harsh chemicals that could damage the stainless steel or diaphragm.
- Cable Integrity: Ensure the cable remains intact and free from kinks or cuts, especially where it connects to the sensor and controller. The polyurethane shielded wire is designed for durability, but physical damage can affect performance.
- Vent Pipe: Verify that the vent pipe in the cable is clear and unobstructed to allow proper atmospheric pressure equalization.
7. Troubleshooting
If you encounter issues with your EARU Level Sensor, consider the following common problems and solutions:
- No Reading/Incorrect Reading:
- Check power supply to both the sensor (10-30 VDC) and the controller (85-260 VAC).
- Verify all wiring connections are secure and correct according to the wiring diagrams.
- Ensure the sensor is fully submerged in the liquid and not obstructed.
- Check for any physical damage to the sensor or cable.
- Confirm the 'Full scale range' (F08) and 'Zero point adjustment' (F09) parameters are set correctly for your application.
- Alarm Not Triggering/Triggering Incorrectly:
- Review the 'Lower limit alarm value' (F00) and 'Upper limit alarm value' (F01) settings.
- Check the 'Alarm delay time' (F04) to ensure it's not set too high, causing a delayed response.
- Pump Not Activating/Deactivating:
- Verify the 'Lower limit pump start value' (F02) and 'Upper limit pump stop value' (F03) are correctly configured.
- Inspect the 'Pump start delay time' (F05) and 'Pump stop delay time' (F06) settings.
- Ensure the pump itself is functional and correctly connected to the controller.
- Communication Issues (RS485):
- Check the RS485 wiring (Blue A-, White B+).
- Verify 'RS485 address' (P03), 'RS485 baud rate' (P04), 'RS485 parity' (P05), and 'RS485 stop bits' (P06) settings match your communication system.
If problems persist, consider performing a 'Factory reset' (P07) after noting down your current settings, or contact customer support.
8. User Tips
- Cable Management: When installing, ensure the cable is routed to avoid sharp bends or excessive tension, which could damage the internal wiring or vent pipe.
- Environmental Considerations: While the sensor is robust, avoid exposing it to corrosive liquids not compatible with stainless steel.
- Calibration: For critical applications, periodically verify the sensor's accuracy against a known reference to ensure continued precise measurements. Use the 'Zero point adjustment' (F09) and 'Full scale adjustment' (F10) for fine-tuning.
- Power Stability: Provide a stable power supply within the specified voltage range to prevent erratic readings or damage to the sensor and controller.
9. Warranty and Support
For warranty information, technical support, or service inquiries, please refer to the documentation provided at the time of purchase or contact your vendor directly. Ensure you have your product model and serial number available for faster assistance.
