1. Product Introduction
1.1 What is the KWS series pH sensor?
The KWS series pH sensor is an intelligent online monitoring device used to measure the acidity and alkalinity of liquids. It integrates advanced technologies such as automatic temperature compensation, digital communication, and long-life electrodes, enabling continuous and accurate monitoring of pH values in various liquids. It provides reliable data support for production processes, environmental protection, and water quality management.
1.2 Core problems solved
● Temperature compensation: The KWS series is equipped with a built-in temperature sensor and automatic temperature compensation, which automatically corrects measurement results according to temperature changes, ensuring data accuracy.
● Network integration: The KWS series adopts an RS485 communication interface and standard MODBUS protocol, allowing easy connection with PLCs, DCS, industrial computers, and other third-party devices for centralized monitoring and data management.
● Easy maintenance: The KWS series uses high-performance industrial online electrodes that require no electrolyte replenishment and offer strong anti-interference capability. They can operate stably for long periods, significantly reducing maintenance workload and extending service life. Once the electrode reaches the end of its service life, it can be directly replaced.
2. KWS Series pH Sensor Parameter Comparison
| Model | KWS-700A | KWS-700B | KWS-750 | KWS-790 |
| Measuring Range | 0 ~ 14 pH | 0 ~ 14 pH | 0 ~ 14 pH | 0.00 ~ 14.00 pH |
| Temperature Range | 0 ~ 50 °C | 0 ~ 50 °C | -5 ~ 65 °C | 1 ~ 100.0 °C |
| Accuracy | ±0.02 pH | ±0.02 pH | ±0.1 pH | ±0.02 pH |
| Resolution | 0.01 pH | 0.01 pH | 0.01 pH | 0.01 pH |
| Working Pressure | < 3 bar | < 3 bar | < 0.2 MPa | – |
| Temperature Compensation | Automatic | Automatic | Automatic | Automatic |
| Output | RS485, MODBUS | RS485, MODBUS | RS485, MODBUS | RS485, 4 ~ 20 mA |
| Installation Method | Immersion installation NPT 3/4 threaded mounting | Immersion installation | Immersion installation NPT 3/4 threaded mounting | Immersion installation Threaded mounting |
| Power Supply | 12 ~ 24 VDC | 12 ~ 24 VDC | 12 ~ 24 VDC | 5V / 12V / 24VDC |
| Wetted Material | POM + Titanium | POM + Titanium | POM | – |
| Cable Length | 10m (customizable) | 10m (customizable) | 5m (customizable) | – |
| Protection Grade | IP68 | IP68 | IP68 | IP68 |
3. Interpretation of Core Parameters
| Parameter | Parameter Meaning | Applicable Scenario Description |
| Measuring Range | Refers to the pH value range that the sensor can measure. All KWS series models cover the commonly used 0–14 pH range, meeting the measurement needs of most liquids. | For example, tap water (pH: 6.5–8.5) can be accurately measured by KWS series pH sensors. |
| Accuracy | Represents the error range of the sensor’s measurement results. Higher accuracy means more reliable data. | KWS-790 has an accuracy of ±0.02 pH and is suitable for high-precision applications such as pharmaceuticals and electronics; KWS-750 has an accuracy of ±0.1 pH and can meet general industrial measurement needs such as wastewater treatment. |
| Temperature Range | Refers to the ambient temperature range in which the sensor can operate normally. | KWS-700A/B (0–50 °C) are suitable for normal-temperature environments such as fish ponds and swimming pool pH monitoring. |
| Working Pressure | Refers to the maximum pressure the sensor can withstand during operation. | For example, in pressurized pipeline water quality monitoring, a sensor with the appropriate pressure rating should be selected to avoid equipment damage. |
4. Step-by-Step Selection Process
Step 1: Clarify measurement requirements
● First, determine the pH range of the measured liquid. If it is within the common 0–14 pH range, all KWS series models can be considered.
● Then confirm accuracy requirements. If the error needs to be controlled within ±0.02 pH, prioritize KWS-700A/B or KWS-790; if accuracy requirements are not high, KWS-750 can meet the needs.
Step 2: Analyze the operating environment
● Temperature: Check the ambient temperature. If it is below 0 °C or above 50 °C, KWS-750 with a temperature range of -5–65 °C is more suitable; if it is a normal-temperature environment (0–50 °C), KWS-700A/B or KWS-790 can be selected.
● Pressure: If measuring in pipelines, confirm the pipeline pressure. For pressure < 3 bar, KWS-700A/B can be used; for pressure < 0.2 MPa, KWS-750 can be selected.
● Installation method: Determine whether threaded installation or immersion installation is required.
Step 3: Confirm communication output requirements
● If the sensor needs to connect to PLCs, DCS, or other systems for centralized monitoring, all KWS series models supporting RS485 and MODBUS protocols are suitable; if the existing system is an analog controller requiring 4–20 mA output, KWS-790 (optional 4–20 mA output) is the most suitable choice.
Step 4: Consider cable length and customization requirements
Check the distance between the sensor installation location and the control system. The standard cable length for KWS-700A/B is 10 m, and for KWS-750 is 5 m. All models support customization. If the installation distance is long, contact us to customize the cable length to avoid insufficient cable length.
Step 5: Consult professionals
● If you are still unsure about the selection, you can consult the KACISE professional technical team. They will provide more targeted recommendations based on your specific requirements and on-site conditions.
5. Typical Application Scenarios
| Application Field | Recommended Model | Reason for Recommendation |
| Aquaculture | KWS-750 | Pressure resistance up to 0.2MPa, suitable for water supply systems with moderate pressure. |
| Water supply systems | KWS-790 | Suitable temperature range and high accuracy. |
| Industrial and pharmaceutical fields | KWS-700 | Wide temperature range and high accuracy, meeting the pH measurement requirements of industrial and pharmaceutical applications. |
6. Summary
To help you quickly identify the appropriate KWS series pH sensor, we briefly review the key points of this guide: by comparing KWS series product parameters, you can initially screen models based on measurement range, accuracy, temperature, and pressure requirements; understanding the meaning of core parameters (range, accuracy, etc.) helps match the most suitable application scenarios; finally, following the five-step selection process (clarify measurement requirements → analyze environment → confirm output → evaluate cable length → consult professionals) can help avoid selection errors. The typical application scenario table provides direct references for common fields, enabling you to quickly find the recommended model.
If you still have questions about sensor selection or need customized solutions based on specific measurement requirements, feel free to contact us directly—our professional team will provide one-on-one guidance to help you choose the most cost-effective pH sensor.
If you are unsure which model to choose, feel free to contact us with your application details for technical support.
