Professional pH/ORP Sensors Manufacturer & Supplier – China Water Quality Monitoring Solutions

Welcome to Dongrun Instrument – a leading pH sensor manufacturer and ORP sensor supplier in China with over 20 years of experience in water quality analysis instrumentation. We specialize in manufacturing high-precision pH electrodes, ORP electrodes, and digital pH/ORP sensors for diverse water quality monitoring applications. Our products are exported to more than 70 countries worldwide, serving municipal water treatment plants, industrial wastewater facilities, swimming pools, food and beverage production companies, pharmaceutical manufacturers, and chemical processing industries.

As an established water quality sensor manufacturer in China, Dongrun is committed to providing reliable, accurate, and cost-effective measurement solutions for all types of water analysis applications. Our pH and ORP sensors are manufactured under strict ISO 9001:2015 quality management system, ensuring consistent performance and long-term stability in even the most challenging environments.

Why Choose Dongrun as Your pH/ORP Sensor Supplier?

Selecting the right pH sensor manufacturer is crucial for ensuring accurate water quality measurements. Dongrun stands out among water quality sensor manufacturers for several compelling reasons:

1. Extensive Industry Experience
With over two decades of experience in water analysis instrumentation, Dongrun has accumulated profound expertise in sensor design, manufacturing, and application. Our R&D team consists of 30+ experienced engineers who continuously innovate to improve sensor performance and reliability.

2. Global Market Presence
Our water quality sensors are trusted by customers in over 70 countries across six continents. This global reach demonstrates our ability to meet diverse international standards and customer requirements.

3. Comprehensive Product Range
As a professional water quality sensor manufacturer, we offer one of the most extensive product lines in the industry, including plastic housing electrodes, glass electrodes, flat-tip electrodes, glass rod electrodes, digital sensors, and explosion-proof transmitters.

4. Quality Certifications
All our pH sensors and ORP sensors meet international quality standards, including ISO 9001:2015, CE, and ATEX certifications for explosion-proof models. Our quality control process ensures every sensor leaves the factory meeting exact specifications.

5. Customization Capabilities
We provide comprehensive OEM and ODM services for bulk orders. Our engineering team can customize sensor specifications, dimensions, cable lengths, and output interfaces to meet your specific application requirements.

6. Technical Support
Our dedicated technical support team provides pre-sales consultation, installation guidance, calibration training, and after-sales troubleshooting to ensure optimal sensor performance throughout the product lifecycle.

Complete pH/ORP Sensor Product Catalog

We offer a comprehensive range of pH sensors and ORP sensors designed for various industrial and municipal applications:

Plastic Housing pH Electrodes

Plastic housing pH electrodes are ideal for general water treatment applications where cost-effectiveness and durability are important. These sensors feature a robust plastic body that resists corrosion and mechanical damage.

Model	Description	Application	Key Features
XS31	Plastic Housing Electrode	Purified water,循环水,污水处理	Economical, durable, general purpose
XS31-S	Sanitary Plastic Electrode	Food & beverage, dairy	Sanitary design, CIP compatible
AS4	Low Ion Plastic Electrode	Pure water,超纯水	Specialized for low conductivity

Glass Electrodes for Industrial Use

Glass pH electrodes offer superior accuracy and faster response compared to plastic electrodes. They are essential for applications requiring precise pH measurement in challenging chemical environments.

Model	Description	Application	Key Features
AB31	Standard Glass Electrode	Standard industrial use	General purpose, reliable
AB11	Basic Glass Electrode	General water monitoring	Wide compatibility
AB19D1	Industrial Glass Rod Electrode	Industrial wastewater	High temperature resistance
AB11D5	Pure Water Glass Electrode	Pure water systems	Fast response, high stability

Specialty Electrodes for Harsh Environments

For applications involving aggressive chemicals, high temperatures, or abrasive media, we offer specialized electrodes designed to withstand extreme conditions.

Model	Description	Application	Key Features
AS93	Flat-tip Desulfation Electrode	Pulp & paper, slurry	Anti-fouling, flat membrane
AS200	Industrial Electrode	Industrial wastewater	Heavy-duty construction
CHB42	High Temp/Pressure Glass Electrode	Chemical processes	Up to 130°C, 6 bar
CHB38	Corrosion Resistant Electrode	Strong acids/alkalis	HF resistant option
DB56	Harsh Process Glass Electrode	Aggressive chemicals	Long life, durable
AB15	Low Temperature Electrode	Brine, cryogenic	Good at 0-30°C

Digital pH/ORP Sensors

Our digital pH sensors feature built-in signal conversion and RS485 output, simplifying system integration and enabling remote monitoring.

Model	Type	Output	Application
PHDS-01	Digital pH/ORP Sensor	RS485 Modbus	System integration
PHDS-02	Digital pH Sensor	RS485, 4-20mA	SCADA integration
DRMP-1000	pH + Conductivity Combo	RS485 Modbus	Multi-parameter

pH/ORP Transmitters

Complete your measurement system with our reliable transmitters and controllers:

PHS-8E – Universal pH/ORP transmitter with digital display, 4-20mA output
PHD-99S-APL – Explosion-proof transmitter for hazardous areas (ATEX certified)
PHS-200 – Multi-parameter controller (pH, ORP, Conductivity, DO)
PHS-300 – Panel mount transmitter with relay outputs

Technical Specifications – pH Sensors

Our pH sensors meet or exceed industry standards for accuracy, reliability, and durability:

Parameter	Specification
Measurement Range	pH 0-14 (standard), extended ranges available
Accuracy	±0.01 pH (standard electrodes)
Reproducibility	±0.01 pH
Response Time	≤10 seconds to 95% (standard), ≤5 seconds (fast response models)
Zero Point	pH 7.00 ± 0.25
Slope	>95% of theoretical (Nernst slope)
Input Impedance	>10¹² Ω
Operating Temperature	0-80°C (standard), 0-130°C (high temp models)
Maximum Pressure	6 bar (standard), up to 16 bar (special models)
Temperature Compensation	PT1000 or NTC (automatic)
Output Signal	Analog: 4-20mA, 0-10V \| Digital: RS485/Modbus
Cable Length	Standard 5m, customizable 1-50m
Connection	PG13.5, 3/4″NPT, or custom
Protection Class	IP68 (submersible models)

Technical Specifications – ORP Sensors

Parameter	Specification
Measurement Range	ORP -2000 to +2000 mV
Accuracy	±1 mV
Reproducibility	±1 mV
Response Time	≤30 seconds to 95%
Operating Temperature	0-80°C
Reference System	Ag/AgCl, Double junction
Electrode Material	Platinum or Gold
Output Signal	4-20mA, RS485/Modbus

pH/ORP Sensor Selection Guide

Choosing the right pH sensor depends on several factors. Use this guide to select the appropriate electrode for your application:

By Application

Municipal Water Treatment
Recommended: AB31, XS31
These models offer the best balance of accuracy, durability, and cost for municipal applications.

Industrial Wastewater
Recommended: CHB42, AS200, AB19D1
Industrial wastewater often contains aggressive chemicals and high temperatures requiring corrosion-resistant electrodes.

Swimming Pool Water
Recommended: AB31, XS31
Standard glass or plastic electrodes work well for pool water monitoring with regular chlorine exposure.

Food & Beverage Production
Recommended: XS31-S (sanitary), AS4
Sanitary-design electrodes with smooth surfaces prevent bacterial growth and allow CIP cleaning.

Pharmaceutical Water (WFI)
Recommended: AS4, AB11D5
Low ionic strength electrodes are essential for accurate pH measurement in pure water.

Chemical Processing
Recommended: CHB42, CHB38, DB56
High-temperature, corrosion-resistant electrodes required for aggressive chemical environments.

Pulp & Paper Industry
Recommended: AS93
Flat-tip electrodes with anti-fouling design prevent clogging from high-solids media.

By Media Characteristics

Clean Water (low solids)
Any standard electrode: AB31, XS31, AB11

High Solids/Slurry
Flat-tip design: AS93

High Temperature (>80°C)
High-temp models: CHB42 (up to 130°C)

Strong Acids or Alkalis
Corrosion-resistant: CHB38, DB56

Low Conductivity (pure water)
Special low-ion electrodes: AS4, AB11D5

Hazardous/Explosive Areas
Explosion-proof: PHD-99S-APL with certified electrode

Installation Methods

Proper installation is crucial for accurate pH measurement. We offer multiple installation options:

1. Immersion Installation
The sensor is mounted on a holder and immersed directly into the process tank or basin. This is the most common method for wastewater and environmental monitoring.

2. Flow-through Installation
The sensor is installed in a flow cell through which sample water flows continuously. This method provides stable measurements and is ideal for clean water applications.

3. Submersible Installation
For deep tanks or outdoor applications, submersible sensors with extended cables are used. These feature IP68 protection for continuous underwater operation.

4. Retractable Installation
Retractable holders allow sensor removal without shutting down the process. Essential for applications requiring frequent calibration or maintenance.

5. Pipe Mounting
Sensors can be installed directly in process pipes using appropriate fittings. Flow cells are typically used for this method.

Maintenance and Calibration

Regular maintenance ensures optimal sensor performance and extends sensor life:

Calibration Frequency

For most industrial applications, pH sensors should be calibrated every 2-4 weeks. In demanding applications or after cleaning, more frequent calibration may be necessary. We recommend:

Two-point calibration using pH 7.00 and pH 4.01 (or pH 10.01 for alkaline applications)
Single-point calibration is acceptable only when the measuring range is limited
Always calibrate after sensor replacement or cleaning

Cleaning Procedures

General Cleaning: Rinse with clean water, gently wipe the glass bulb with soft cloth.

Mineral Deposits: Soak in 5% HCl or HNO3 solution for 15-30 minutes, then rinse thoroughly.

Organic Contamination: Clean with acetone or methanol, then condition in pH 7 buffer.

Grease/Oil: Wash with mild detergent, rinse thoroughly.

Storage

Short-term: Store in pH 4 or pH 7 buffer solution.
Long-term: Keep in storage solution (pH 4 KCl). Never allow the electrode to dry out.

Expected Sensor Life

With proper maintenance, sensor lifespan varies:

Plastic electrodes: 1-2 years
Glass electrodes: 2-3 years
Digital sensors: 3-5 years
Specialty electrodes: 1-3 years (depending on application)

Note: Harsh conditions (high temperature, strong chemicals, abrasion) will shorten sensor life.

Factory Production Capabilities

Dongrun Instrument Co., Ltd. is a modern water quality sensor manufacturer with comprehensive production capabilities:

Factory Area: 10,000 square meters of manufacturing space

Annual Production Capacity: 50,000+ sensors annually

Quality Management: ISO 9001:2015 certified

Certifications: CE, ATEX (explosion-proof models)

R&D Team: 30+ engineers specializing in sensor technology

Testing Facilities: Advanced calibration and testing equipment

Production Equipment: Automated assembly lines, precision testing instruments

Applications Across Industries

Our pH sensors and ORP sensors serve critical monitoring functions across diverse industries:

Municipal Water Treatment

In municipal water treatment plants, pH measurement is essential for optimizing chemical dosing in coagulation, flocculation, and disinfection processes. ORP sensors monitor the oxidation potential to ensure effective chlorine disinfection. Our sensors help ensure safe drinking water quality and compliance with regulatory standards.

Industrial Wastewater Treatment

Industrial wastewater treatment requires robust pH control for effective pollutant removal. Our industrial-grade sensors withstand the harsh chemicals and variable conditions common in wastewater treatment processes, helping facilities maintain discharge compliance.

Swimming Pool Water Quality

Proper pH balance (7.2-7.6) is critical for swimmer comfort and effective chlorine disinfection. Our sensors help pool operators maintain optimal water quality, extending chlorine effectiveness and preventing eye and skin irritation.

Food and Beverage Production

pH control is fundamental in food processing for safety, quality, and shelf life. From fruit juice processing to dairy production, our sanitary sensors ensure accurate measurements while meeting hygiene requirements.

Pharmaceutical Water Systems

Pharmaceutical water systems (Purified Water and Water for Injection) require extremely precise pH monitoring. Our low-ion electrodes provide the accuracy needed for these critical applications.

Chemical Processing

Chemical processes require precise pH control for reaction optimization and safety. Our corrosion-resistant electrodes handle aggressive chemicals and high temperatures found in chemical manufacturing.

Power Generation

In power plants, pH control in boiler feedwater and cooling water systems prevents corrosion and scale formation. Our high-temperature sensors perform reliably in these demanding conditions.

Aquaculture

Optimal pH levels are essential for fish health and growth in aquaculture operations. Our sensors help maintain water quality for healthy aquatic environments.

Frequently Asked Questions (FAQ)

Q: What is the difference between pH and ORP measurement?

A: pH measures the hydrogen ion activity in a solution, indicating how acidic or alkaline the water is on a scale of 0-14. pH 7 is neutral, below 7 is acidic, and above 7 is alkaline. ORP (Oxidation-Reduction Potential) measures the ability of a solution to oxidize or reduce substances, expressed in millivolts (mV). While pH indicates the acidity/alkalinity, ORP indicates the disinfecting capability of oxidizing agents like chlorine. Both measurements are complementary for comprehensive water quality analysis.

Q: How do I choose between plastic and glass pH electrodes?

A: Glass electrodes offer faster response, higher accuracy, and wider measurement range, making them suitable for most industrial applications. Plastic electrodes are more durable, cost-effective, and resistant to mechanical damage, making them ideal for municipal water treatment, wastewater, and applications where the sensor may be subjected to rough handling. For pure water applications, specialized low-ion glass electrodes (like AS4 or AB11D5) are recommended.

Q: What causes slow response or inaccurate readings in pH sensors?

A: Several factors can cause pH sensor problems: (1) Coated or fouled glass membrane – clean according to the cleaning procedures; (2) Dehydrated glass membrane – soak in pH buffer to rehydrate; (3) Clogged reference junction – clean or replace; (4) Reference solution contamination – check for leaks; (5) Temperature mismatch between sensor and solution – allow equilibration; (6) Ground loop or electrical interference – check wiring and grounding.

A: Calibration frequency depends on application conditions. General guidelines: (1) Clean water applications: every 4-8 weeks; (2) Wastewater treatment: every 2-4 weeks; (3) Harsh chemical processes: every 1-2 weeks; (4) After any maintenance or cleaning; (5) When accuracy seems off. Always calibrate after replacing a sensor.

Q: What is the expected lifespan of a pH electrode?

A: Under normal conditions: plastic electrodes last 1-2 years, glass electrodes 2-3 years, and digital sensors 3-5 years. Harsh conditions (high temperature, strong chemicals, abrasion) will shorten lifespan. Proper maintenance and storage can significantly extend sensor life.

Q: Do you offer OEM/ODM manufacturing services?

A: Yes, we provide comprehensive OEM and ODM services for bulk orders. We can customize: sensor dimensions and specifications, cable lengths and connectors, output signals and protocols, packaging and branding. Minimum order quantities vary by customization level. Contact us to discuss your requirements.

A: For standard catalog models: 7-15 business days. For customized sensors: 15-30 business days depending on specifications. For bulk OEM orders: lead time is negotiated based on quantity and customization requirements. Express shipping options are available for urgent orders.

Q: What payment methods do you accept?

A: We accept T/T (Telegraphic Transfer), L/C (Letter of Credit), PayPal (for small orders), and Western Union. For first-time customers, we typically require 30% deposit with balance paid before shipment.

A: Key installation guidelines: (1) Install at a location with good sample flow; (2) Ensure the sensor is fully immersed in the process medium; (3) Avoid installation near bubbles or turbulence; (4) Mount at 15-45 degree angle (never horizontal or upside down); (5) Keep the glass bulb away from walls or tank bottom; (6) Ensure proper grounding; (7) Follow local electrical codes for wiring. Detailed installation guides are provided with each sensor.

A: Our sensors use standard industry connections and can integrate with most transmitters that accept standard pH/ORP electrodes. However, we recommend using our matched transmitter/electrode combinations for optimal performance. Contact our technical team for compatibility verification.

Ordering Information

To place an order or request a quote, please provide:

Target application and media characteristics
Required measurement range
Operating temperature and pressure
Output signal requirements (4-20mA, RS485, etc.)
Installation method
Quantity
Any special requirements (cable length, connectors, certifications)

Contact Information

We welcome inquiries from distributors, system integrators, and end users worldwide. Contact us today for competitive pricing and technical support:

Company: Dongrun Instrument Co., Ltd.
Address: Dongguan, Guangdong, China
Email: info@dongrun-instrument.com
Phone: +86-769-23028868
WhatsApp: +86-15098687108
Website: www.dongrun-instrument.com