1. Introduction
The ComWinTop CWT-BL-PH is a sophisticated water PH and temperature transmitter designed for accurate and reliable monitoring in various industrial and environmental applications. This module utilizes a double high-impedance three-electrode system, offering online one-key calibration, real-time temperature compensation, and robust power-off protection. It provides multiple output options including 0-5V, 0-10V, 4-20mA, and RS485, making it versatile for integration with different monitoring equipment.
Figure 1: ComWinTop CWT-BL-PH Water PH Temperature Transmitter with PH electrode and temperature probe.
Video 1: Overview of the CWT-BL-PH Water PH Temperature Transmitter components.
2. Key Features
- Double high-impedance three-electrode system.
- Online one-key calibration for ease of use.
- Real-time temperature compensation.
- Electrode loose alarm and electrode health status alarm during calibration.
- Power-off protection: Calibration results and preset data are retained.
- Overcurrent and overvoltage protection.
- High measurement accuracy and fast response.
- Long operational life.
- Compact size, light weight, and easy installation.
- Standard industrial signal outputs: 0-5V, 0-10V, 4-20mA, and RS485.
3. Specifications
Figure 2: Technical Specifications Table.
| Item | Parameter |
|---|---|
| Temperature measurement range | -20°C ~ +80°C |
| Temperature measurement accuracy | ±0.5°C |
| Measurement PH range | 0.0 ~ 14.0PH |
| Measuring PH Accuracy | ±0.01PH |
| Power supply | DC 12V-24V |
| Output | 0-5V / 0-10V / 4-20mA / RS485 |
| Load resistance | Voltage output: R load ≥ 10K Ω Current output: R loads(Uvcc-3)/0.02Ω |
| Consumption | <1W |
| Storage condition | 10-50°C (-20-+80C peak) 20-60%RH |
| Working environment | -20°C ~ +80°C |
| Dimension | 65 X 46 X 28.5mm³ |
3.1. Dimensions
Figure 3: Transmitter Module Dimensions (Length: 65mm, Width: 44.9mm, Height: 28.5mm). The temperature probe cable length is 5 meters.
Figure 4: PH Electrode Dimensions (Overall length: 160mm, Diameter: 25mm/28mm).
4. Product Overview and Components
The CWT-BL-PH system typically includes:
- Transmitter Module: The main processing unit that converts sensor signals into standard output signals.
- PH Electrode: A BNC-connected probe for measuring the pH level of water.
- Temperature Probe: A separate probe for measuring water temperature, often with a 5-meter cable.
Figure 5: Complete CWT-BL-PH Kit.
5. Setup and Installation
5.1. Wiring
The transmitter module features a terminal block for power input and output connections. Ensure correct polarity and voltage (DC 12V-24V) when connecting the power supply. Connect the PH electrode to the BNC connector on the module. The temperature probe connects to the dedicated terminals on the module.
Refer to the markings on the transmitter module for specific wiring connections for 0-5V, 0-10V, 4-20mA, or RS485 outputs. Ensure all connections are secure to prevent signal interference or damage.
Figure 6: Transmitter Module and Temperature Probe Connection.
5.2. Mounting
The compact design of the transmitter module allows for easy installation in various setups. It can be mounted using screws through the designated holes or potentially clipped into a compatible rail system if available (check for specific mounting accessories). Ensure the module is placed in a location that is protected from excessive moisture and extreme temperatures, within the specified working environment range of -20°C to +80°C.
6. Operation
6.1. Power-Up and Initial Check
Once wired and mounted, apply power to the transmitter. The module should power on. Monitor the output signals using appropriate receiving equipment (e.g., PLC, data logger, display unit) to confirm basic functionality.
6.2. Calibration
The CWT-BL-PH features an online one-key calibration function. This is crucial for maintaining accuracy, especially for the PH electrode. The system also includes real-time temperature compensation to ensure accurate readings across varying temperatures.
During calibration, the system provides alarms for a loose electrode or if the electrode is faulty, aiding in troubleshooting.
6.3. Interpreting Output Signals
The transmitter provides linear analog outputs for both PH and temperature. Use the following formulas and tables to convert the analog output signals to their corresponding physical values:
PH Value Conversion:
- 0-5V Output: PH = (PH output voltage) * 2.8
- 0-10V Output: PH = (PH output voltage) * 1.4
- 4-20mA Output: PH = (PH output current - 4.0) * 0.875
Figure 7: PH Measurement Range and Output Values.
Temperature Value Conversion:
- 0-5V Output: Temperature = (temperature output voltage) * 20.0 - 20.0
- 0-10V Output: Temperature = (temperature output voltage) * 10.0 - 20.0
- 4-20mA Output: Temperature = (temperature output current - 4.0) * 6.25 - 20.0
Figure 8: Temperature Measurement Range and Output Values.
7. Maintenance
7.1. Regular Calibration
Due to the PH electrode's susceptibility to pollution in the measurement environment, regular calibration is essential to ensure long-term accuracy. It is generally recommended to perform a transducer calibration once a month. The specific calibration cycle may vary depending on the water samples being monitored.
7.2. Electrode Cleaning
Periodically inspect and clean the PH electrode to remove any buildup or contaminants that could affect readings. Follow standard procedures for cleaning PH electrodes, typically involving rinsing with distilled water and, if necessary, using a mild cleaning solution.
7.3. Storage Conditions
When not in use, store the module and electrodes within the specified storage conditions: 10-50°C (-20-+80°C peak) and 20-60%RH. Ensure electrodes are stored properly according to their individual instructions (e.g., in a storage solution for PH electrodes).
8. Troubleshooting
- No Output/Incorrect Readings:
- Verify power supply (DC 12V-24V) is correctly connected and within range.
- Check all wiring connections for looseness or incorrect polarity.
- Ensure the PH electrode and temperature probe are properly connected to the module.
- Perform a calibration to rule out electrode drift or contamination.
- Electrode Loose Alarm:
- If an alarm indicates a loose electrode during calibration, check the BNC connection of the PH electrode to ensure it is securely fastened.
- Electrode Good/Bad Alarm:
- If an alarm indicates a faulty electrode during calibration, the PH electrode may need cleaning or replacement.
- Inconsistent Readings:
- Ensure the electrodes are fully immersed in the sample.
- Check for air bubbles around the electrode.
- Verify the sample temperature is stable or that temperature compensation is functioning correctly.
- Consider the frequency of calibration; increased pollution may require more frequent calibration.
9. User Tips
- This device is designed for wired integration into monitoring systems. It does not support Wi-Fi or direct smartphone connectivity.
- To visualize measured values, connect the transmitter's output (0-5V, 0-10V, 4-20mA, or RS485) to a compatible display unit, PLC, or data acquisition system.
- Always ensure the PH electrode is kept moist when not in use, typically by storing it in a suitable storage solution, to prolong its lifespan.
10. Applications
This product is suitable for a wide range of applications requiring precise pH and temperature monitoring, including but not limited to:
- Electroplating
- Yeast cultivation
- Food processing
- Sewage treatment
- Metallurgy
- Environmental protection
- Aquaculture
11. Warranty and Support
For warranty information, technical support, or service inquiries, please contact your vendor or the manufacturer directly. Keep your purchase receipt and product model number (CWT-BL-PH) handy for faster assistance.
A detailed user manual in PDF format may be available for download from the manufacturer's website or provided by your seller. Please refer to this document for comprehensive instructions and advanced configurations.