PRE643-PH Online Digital pH Sensor

Introduction

The PRE643-PH is a high-precision online digital pH sensor designed for continuous, real-time monitoring in demanding industrial environments. Built with a rugged industrial-grade electrode and a built-in temperature sensor for automatic temperature compensation, it ensures accurate and reliable pH readings even in challenging conditions. With support for RS-485 Modbus digital output, the PRE643-PH offers seamless integration into existing systems, making it a smart choice for industries requiring high-performance pH measurement.

Key Features of the PRE643-PH Sensor

• ✔ High Accuracy: ±0.05 pH with 0.01 resolution

• ✔ Automatic Temperature Compensation (ATC): Ensures reliable readings under temperature variations

• ✔ RS-485 Modbus Communication: Digital output for long-distance and noise-resistant data transmission

• ✔ Durable Design: IP68-rated housing, POM + Titanium construction

• ✔ Quick Response Time: ≤ 5 seconds

• ✔ Easy Installation & Calibration: Supports two-point and three-point calibration

Technical Specifications

Cable Definition

The PRE643-PH sensor uses a 4-wire shielded cable (AWG-24 or AWG-26) with a 5.5mm outer diameter. The wire configuration is as follows:

Application Areas of PRE643-PH

The PRE643-PH pH sensor is ideal for continuous pH monitoring in the following industries:

1. Water & Wastewater Treatment

• Ensure compliance with environmental regulations

• Monitor pH in potable and industrial water treatment systems

2. Chemical Industry

• Maintain pH control in chemical production and waste neutralization

3. Food & Beverage

• Ensure product quality and safety during food and beverage processing

4. Aquaculture & Hydroponics

• Optimize water pH to enhance fish farming and plant growth

5. Pulp & Paper

• Maintain consistent paper quality with precise pH control

6. Pharmaceuticals & Laboratories

• Ensure precision in research and product manufacturing processes

Benefits of the PRE643-PH Sensor

✅ Exceptional Accuracy – Reliable Performance in Every Condition

The PRE643-PH sensor is engineered for high-precision pH measurement, delivering reliable data even in challenging environments such as high humidity, high pressure, or submerged conditions. With an accuracy of ±0.05 pH and a resolution of 0.01, it ensures consistent, dependable readings essential for critical industrial processes like water treatment, chemical production, and pharmaceutical manufacturing. This high level of accuracy helps reduce process variability, improve quality control, and enhance overall system efficiency.

✅ Robust and Waterproof Design – Built to Last

Constructed with an industrial-grade housing made from POM (Polyoxymethylene) and titanium, and certified with IP68 waterproof protection, the PRE643-PH sensor is designed to operate reliably in the harshest environments. Whether it’s fully submerged in water, exposed to corrosive substances, or installed in outdoor settings, the sensor maintains its structural integrity and measurement reliability. This rugged construction greatly reduces the risk of sensor failure and extends operational lifespan, making it a cost-effective investment.

✅ Automatic Temperature Compensation – Consistent Readings Across Temperature Ranges

Thanks to its integrated temperature sensor, the PRE643-PH provides automatic temperature compensation (ATC). This feature adjusts pH readings in real-time to account for the effects of temperature on sensor accuracy, ensuring stable and accurate data across a wide temperature range (0–80°C). This is particularly important in applications where temperature fluctuations are common, such as wastewater treatment or industrial processing environments.

✅ User-Friendly Setup and Low Maintenance – Time-Saving Operation

The PRE643-PH is designed for easy installation and minimal upkeep. With support for both two-point and three-point calibration methods, users can quickly calibrate the sensor to meet their specific process requirements. The 10-meter default cable length (customizable upon request) and standard RS-485 interface make it simple to integrate into existing systems. Its durable design also means reduced maintenance frequency, saving time and labor costs over the long term.

✅ Seamless Digital Integration – Smart Connectivity via RS-485 Modbus

Equipped with RS-485 communication and Modbus RTU protocol, the PRE643-PH allows for reliable and interference-resistant data transmission over long distances. This makes it highly suitable for remote monitoring, automated control systems, and integration with SCADA/PLC platforms. The sensor’s digital output ensures quick response times and real-time monitoring, improving operational visibility and system efficiency.

Conclusion

The PRE643-PH is an advanced solution for industries seeking accurate, stable, and long-term pH measurement. With its durable construction, smart digital output, and automatic temperature compensation, this sensor delivers consistent performance across a wide range of industrial applications.

✅ Learn more:

PRE917B Automatic Water Sampler