Industrial-grade Online Water Quality Analysis Tool: Yexsensor YEX-TH-406 Total Hardness Sensor

In the fields of industrial circulating water, boiler makeup water, and environmental monitoring, real-time monitoring of total water hardness (calculated as CaCO3) is the key to preventing system scaling and ensuring production safety. The Yexsensor YEX-TH-406 is an online total hardness monitoring terminal specially designed for harsh working conditions. It adopts advanced ion selective electrode (ISE) technology and provides global system integrators with a stable, accurate, and highly cost-effective digital solution.

Core Product Advantages and Technical Features

1. Patented Calcium Magnesium Ion Selective Electrode (ISE)
       The YEX-TH-406 adopts the patented PVC membrane calcium and magnesium selective electrode developed by Yexsensor. Its internal reference solution slowly seeps out through a microporous salt bridge under a pressure of at least 100KPa (1Bar). This unique reference system design effectively solves the common problems of electrode contamination and poisoning in industrial sites, ensuring ultra-long service life and extremely high measurement stability of the electrode under complex working conditions.

2. Standardized Digital Output, Seamless Integration
       The sensor has a built-in high-performance processor and directly outputs standard RS-485 Modbus RTU signals.

• High compatibility: Can be directly connected to PLC, DCS, industrial control computers, touch screens, and other third-party devices.

• Long-distance transmission: Digital signals have strong anti-interference ability and support signal transmission up to hundreds of meters without loss of accuracy.

• Optional analog output: Simultaneously supports 4-20 mA current output to meet the access requirements of traditional automation systems.

3. Precise and Reliable Compensation System
       The sensor has a built-in Pt1000 temperature sensor, providing full-range automatic temperature compensation. Whether in low-temperature winter conditions or high-temperature circulating water in summer, it ensures the authenticity and consistency of measurement results.

4. Industrial-grade Protection and Convenient Installation
       Protection rating: IP68, supports long-term submersible installation.
       Reliable materials: POM/ABS or 316L stainless steel housing options, adapting to different corrosive water qualities.
       Specification: Standard 3/4 NPT pipe thread, simplifying deployment in pipelines, tanks, or open water tanks.

Yexsensor YEX-TH-406 Online Total Hardness Sensor Technical Specifications

Yexsensor YEX-TH-406 Online Total Hardness Sensor Typical Application Scenarios

• Industrial Boilers and Thermal Systems
         In boiler feedwater systems, excessively high hardness can cause rapid scaling on heating surfaces, reduce thermal efficiency, and even lead to tube burst accidents. The YEX-TH-406 can monitor the quality of softened water outlet in real time to ensure that the water entering the boiler meets national and industry standards.

• Reverse Osmosis (RO) Pretreatment
         In membrane water treatment, hardness monitoring is an important basis for controlling the dosage of scale inhibitors. Through the real-time feedback of the Yexsensor sensor, the dosing system can be precisely optimized, extending the service life of RO membranes and reducing operating costs.

• Smart Water Management and Water Treatment Plants
         Online monitoring of total hardness in pipe network water and finished water to ensure the sensory properties of residents' drinking water and compliance with hygiene standards, while providing digital support for water supply scheduling.

• Wastewater Treatment and Reclaimed Water Reuse
         In wastewater treatment processes of chemical, electroplating, and printing and dyeing industries, monitoring the total hardness of effluent is a key link to ensure the stable operation of reclaimed water reuse systems.

Installation and Wiring Guidelines

Installation Angle Requirements

Note: The sensor must not be installed upside down or horizontally. To ensure normal distribution of the internal electrolyte and automatic discharge of air bubbles, the installation angle should be kept at more than 15° from the horizontal plane.

5-core Twisted Shielded Cable Wiring Definition

• Red wire: Power supply (12～24VDC)

• Black wire: Ground (GND)

• Blue wire: 485A

• White wire: 485B

• Yellow wire: Current output (optional)

Maintenance and Calibration Recommendations

Initial Activation: New electrodes must be powered and soaked in tap water for 48 hours for activation before use, then rinsed with deionized water before measurement.

Daily Maintenance: Regularly check the dryness of wiring terminals. If there are deposits on the sensing membrane, rinse with deionized water. Do not scratch the PVC membrane with hard objects.

Calibration Cycle: It is recommended to perform zero point and slope calibration (two-point calibration method) regularly according to on-site water quality conditions.

FAQ

Q1. Can the YEX-TH-406 measure extremely high salinity seawater?

The sensor is suitable for ordinary industrial water and freshwater environments with pH 4-10. If the water contains extremely high concentrations of interfering ions (such as high sodium and high chloride in seawater), it may affect measurement accuracy and electrode life. Please consult technical support before special applications.

Q2. Why must the sensor be installed at an angle?

Tilted installation ensures that the sensing element at the electrode head is always immersed in the internal electrolyte and prevents air bubbles from accumulating on the sensitive membrane surface. Horizontal or inverted installation will cause reading drift or sensor failure.

Q3. What is the expected service life of the electrode?

Ion selective electrodes are consumables. Under normal working conditions and proper maintenance, the electrode life is usually 6-12 months. Yexsensor's patented pressure compensation system significantly improves its durability.

Q4. Can I connect the sensor directly to my PLC?

Yes. The YEX-TH-406 uses the standard RS-485 Modbus RTU protocol. As long as your PLC supports this communication protocol, you can directly read real-time concentration and temperature data.

Q5. How should the electrode be stored if not used for a long time?

If not used for more than two weeks, the electrode should be stored dry and must be covered with the original factory protective cap with a protective pad to prevent damage to the sensitive membrane.

Q6. How fast is the sensor's response time?

Its T90 response time is less than 60 seconds. In actual online monitoring, this is sufficient to capture sudden changes in water hardness and trigger system protection.

Q7. Can the cable provided with the product be extended?

The standard cable length is 5 meters. We can customize longer cables according to your site requirements, or you can extend it yourself through a waterproof junction box (it is recommended to use shielded twisted pair to ensure signal quality).

Q8. What should I do if there is a measurement error?

Two-point calibration (zero point and slope) can be performed through Modbus commands. We recommend using standard solutions of known concentration for calibration. Please refer to the communication protocol manual attached to the product for specific instructions.

Quality Assurance and After-sales Service

Full inspection: Every Yexsensor sensor undergoes 72-hour aging and stability tests before leaving the factory to ensure a 100% pass rate.

Warranty commitment: One-year warranty for the whole machine, and six-month warranty for the electrode (consumable).

Brand support: As a professional sensor series under NiuBoL, we provide complete and professional technical documentation and remote integration support.