Industrial Online pH Sensor RS485 Modbus | YEX-S1-PH

Yexsensor YEX-S1-PH: Industrial Long-Life Online pH Sensor

YEX-S1-PH is an industrial online pH and temperature sensor for continuous wastewater, process-water and aquaculture monitoring. It provides RS485 Modbus RTU output for PLC, SCADA and data-logging systems, with a 0.00-14.00 pH range, automatic temperature compensation and submersible installation. Buyers should confirm the water matrix, mounting point, cable distance, calibration plan and controller register requirements before quotation.

Where It Fits in the YexSensor Line

Series positioning: YEX-S1-PH belongs to the S1 standard series — YexSensor's cost-effective line of online water quality probes in an IP68 engineering-plastic housing, built for high-volume monitoring points in municipal, industrial and agricultural water. For seawater, high-chloride or oily duty that demands 316L stainless-steel construction, step up to the S1 PRO stainless-steel series; for dual-interface RS485 + 4–20 mA projects, see the S2 flagship series.

Core Technical Advantages: Designed for Complex Working Conditions

1. Patented Long-Life Reference System (Exclusive Advantage)

Ordinary industrial pH electrodes often fail due to excessively fast loss or contamination of the reference solution. Yexsensor’s patented design ensures that the internal reference solution seeps out slowly from the microporous salt bridge at an extremely small rate under a pressure of ≥100KPa (1Bar).

• Ultra-long life: Forward seepage can last more than 20 months, and the service life is doubled compared to ordinary industrial electrodes.

• High stability: Positive pressure seepage effectively prevents the measured medium from permeating and contaminating the inside of the electrode, greatly reducing maintenance frequency.

2. Dual High-Impedance Differential Amplifier

Aimed at the complex electromagnetic environment of industrial sites, the YEX-S1-PH adopts advanced dual high-impedance differential amplification circuit:

• Strong anti-interference: Effectively suppresses common-mode interference generated by industrial motors and frequency converters.

• Sensitive response: T90 response time is less than 30 seconds, reflecting pH fluctuations in chemical reactions in real time.

3. Digitalization and Intelligent Compensation

Standard communication: Supports RS-485 (Modbus RTU) protocol, easily connecting to PLC, DCS and cloud monitoring systems.

Temperature correction: Built-in Pt1000 automatic temperature compensation ensures that measurement accuracy is always maintained at ±0.1 pH under temperature fluctuations of 0-50°C.

YEX-S1-PH Industrial Online pH Sensor Application Scenarios and Solutions

YEX-S1-PH can meet the stringent requirements of most industrial applications:

• Industrial Wastewater and Environmental Monitoring
  In the treatment of acid, alkali, salt solutions and discharge monitoring, the sensor shows excellent stability. The IP68 protection rating supports long-term submersible operation without fear of harsh environments.

• Chemical Reaction Process Control
  In fine chemical and pharmaceutical processes, small deviations in pH value may lead to reaction failure. The high-precision reading of the Yexsensor sensor can serve as a reliable input source for closed-loop dosing systems.

• Industrial Circulating Water and Desulfurization & Denitrification
  Used to monitor the scaling tendency of cooling circulating water or the pH value of slurry in flue gas desulfurization systems to protect pipeline equipment from corrosion.

YEX-S1-PH Industrial Online pH Sensor Technical Performance Parameters

YEX-S1-PH Industrial Online pH Sensor Installation Guide and Electrical Connection

Standard Installation Key Points

Angle requirement: The sensor must not be installed upside down or horizontally. To ensure normal pressure of the electrolyte inside the electrode and to remove air bubbles, the installation angle should be tilted more than 15 degrees from the horizontal plane.

Environmental preparation: Before installation, please ensure that the 3/4 NPT thread connection is well sealed to prevent water leakage.

Electrical Wiring Definition (4-core Shielded Cable)

• Red wire: Power positive pole (V+)

• Black wire: Power negative pole (GND)

• Blue wire: RS-485 A (Signal +)

• White wire: RS-485 B (Signal -)

Wiring tips: All wiring points must be strictly waterproofed. If the cable is exposed or immersed in corrosive liquids for a long time, it is recommended to add additional protective sleeves.

YEX-S1-PH Industrial Online pH Sensor Maintenance and Care Recommendations

Daily Cleaning and Activation

First use: Before measurement, please clean with distilled water and dry with filter paper. The recommended immersion depth is at least 1/3 of the electrode length.

Electrode cleaning: If deposits or semi-transparent film appear on the glass membrane after long-term use, it can be briefly washed with dilute hydrochloric acid and rinsed thoroughly. Do not contact with organosilicon grease.

Storage Specifications

Short-term storage: When the sensor is not in use, it should be cleaned and inserted into a protective sleeve containing 3mol/L potassium chloride (KCl) solution.

Long-term storage: Ensure that the electrode bulb remains moist at all times. Do not store dry to prevent glass membrane failure.

YEX-S1-PH Project Data for Quotation

For sensor selection and quotation, provide the water matrix, expected pH range, normal operating temperature, installation method, cable distance, power supply, RS485 Modbus integration requirements, quantity and destination country.

Review the RS485 Modbus integration FAQ before confirming the PLC or SCADA connection. For project support, Send Your Project Requirements.

YEX-S1-PH Selection, Integration and Procurement FAQ

Q1: How long is the typical electrode life of the YEX-S1-PH sensor?

A1: Thanks to our patented seepage system, the reference solution can work stably for more than 20 months. Actual life depends on working conditions (such as high temperature, strong acid and alkali), but in standard industrial environments, its life far exceeds that of ordinary industrial electrodes.

Q2: Why can't the sensor be placed horizontally during installation?

A2: Horizontal installation easily generates air bubbles inside the glass electrode bulb, resulting in poor contact between the electrode and internal liquid, thus causing large reading jumps or measurement errors.

Q3: Can the standard cable length be customized?

A3: Yes. The standard length is 5 meters. We can provide personalized cable customization according to your site distance.

Q4: Has the sensor been calibrated before leaving the factory?

A4: Yes. The sensor is calibrated before shipment, but commissioning verification and periodic calibration are still required. Set the interval according to the water matrix, fouling rate, accuracy requirement and site quality procedure.

Q5: What standard powders need to be prepared for calibration?

A5: Usually pH 6.86 (neutral), pH 4.00 (acidic) or pH 9.18 (alkaline) standard buffer solutions are required. Please choose two-point calibration according to the range of the liquid to be measured.

Q6: How to deal with dirt on the electrode glass membrane?

A6: If it is inorganic salt deposits, rinse with dilute hydrochloric acid; if it is oily substances, it is recommended to wipe the wiring terminals with alcohol instead of the electrode membrane. After cleaning, reactivation in KCl solution is required.

Q7: How to troubleshoot unstable RS-485 communication?

A7: Check whether the power supply voltage is stable (12-24V), confirm whether 485A/B is reversed, and ensure that the shielding layer is reliably grounded to filter electromagnetic interference.

Q8: What are the signs of sensor failure?

A8: When the electrode cannot pass calibration, remains unstable after cleaning, or responds abnormally slowly, inspect the glass bulb, reference junction, cable and installation before replacement. Replace the electrode only after cleaning, wiring and buffer checks fail to restore normal performance.

Q9: What information should a buyer provide before requesting a quotation?

A9: Provide the water matrix, expected pH range, temperature, mounting method, cable length, power supply, Modbus integration requirement, quantity and destination. These inputs determine the installation accessories, cable configuration and integration scope.

Q10: Where should the YEX-S1-PH probe be installed?

A10: Install it where the sample is representative and continuously contacts the sensing end, while avoiding trapped air, sediment burial and direct impact from pumps or chemical injection. Confirm whether the project needs submersible, tank or flow-through installation before ordering.

Quality Commitment and Service

Aging test: Every product undergoes 72-hour high-temperature aging test to ensure circuit stability.

After-sales guarantee: One-year warranty from the date of sale.

Accessory list: Yexsensor sensor (1 pc), 5-meter shielded cable (1 pc), instruction manual, certificate of conformity.

YexSensor Application Guidance for Online pH Monitoring

The YEX-S1-PH online pH sensor is suitable for wastewater treatment, aquaculture, river monitoring, industrial process water and general water quality control. pH is one of the most widely used basic water quality parameters because it reflects acidity and alkalinity changes. In many projects, pH data is combined with dissolved oxygen, conductivity, COD or ammonium nitrogen data to support a more complete water quality evaluation.

Summary

Choose YEX-S1-PH when a project requires continuous industrial pH and temperature monitoring with RS485 Modbus RTU integration. Confirm the water matrix, expected range, mounting point, cable distance, calibration procedure, PLC or SCADA register requirements and order quantity before quotation. Installation must keep the probe in representative water and maintenance frequency should be based on fouling and accuracy requirements.