How to Select pH Sensors for Hydrofluoric Acid Water? Complete HF-Resistant Monitoring Solution

2026-07-27

Scenarios such as photovoltaic etching, semiconductor cleaning and fluorochemical acid pickling produce water containing hydrofluoric acid. Ordinary pH electrodes are susceptible to corrosion by fluoride ions, resulting in data drift and rapid failure. Conventional monitoring instruments feature weak anti-interference performance, lack automatic chemical dosing control and data recording functions, leading to high manual operation and maintenance costs. Most commercially available HF-resistant electrodes are only suitable for low-concentration HF below 1000 ppm. Separate procurement of transmitters and electrodes also brings risks of signal incompatibility.

Chunye Technology independently developed the T6000 online pH/ORP transmitter, which forms a complete monitoring system with three types of HF-resistant pH electrodes: CS1528 glass electrode, CS1728FC plastic electrode and CS1737C antimony plastic electrode.CS1528 / CS1728FC can withstand HF concentration up to 4000 ppm, while the newly launched CS1737C is specially designed for ultra-high HF concentration conditions above 4000 ppm. All products adopt in-depth hardware and software adaptation, enabling long-term online monitoring, automatic dosing and data traceability for fluorine-containing water in one-stop mode, covering working conditions of 0\130℃ and 0\0.6 MPa.

1. HF-Resistant Electrode Hardware: CS1528 / CS1728 / CS1737 Series for HF Corrosive Conditions

CS1528 and CS1728FC adopt fluorine-modified glass membranes, and CS1737C uses antimony measuring elements. Signals of the three electrodes can be directly connected to the T6000 transmitter without adapters.

Matching by membrane resistance / measuring element according to temperature zone and HF concentration

CS1528FC/FCT: Membrane resistance ＜80 MΩ, for conventional fluorine-containing wastewater at 0~100℃, HF ≤ 4000 ppm;
CS1528C/CT: Membrane resistance ＜50 MΩ, dedicated for high-temperature reactors at 0~130℃, HF ≤ 4000 ppm;
CS1728FC plastic electrode: For pipeline / tank immersion applications at 0~80℃, impact-resistant housing, HF ≤ 4000 ppm;
CS1737C antimony plastic electrode: Antimony sensing material, designed for ultra-high hydrofluoric acid environments with HF＞4000 ppm, applicable temperature 0\80℃, pressure resistance 0\0.3 MPa.

Stable HF resistance performance

CS1528, CS1728FC: Maximum HF tolerance 4000 ppm, measuring range 0~12 pH, zero point 7.00±0.25;
CS1737C: Suitable for HF＞4000 ppm conditions, measuring range 2~12 pH, zero point 7.00±0.25;All models support optional NTC10K / NTC2.2K / PT100 / PT1000 temperature compensation probes, compatible with the automatic temperature compensation function of T6000.

Universal connectors for transmitter adaptation

Cables support BNC, pin terminal and tinned terminal types; shielded cables of 5~20 m are optional. All three electrodes can be directly connected to the T6000 controller to avoid industrial electromagnetic interference.

2. Matched Control Transmitter: Core Functions of T6000 Industrial pH/ORP Transmitter

Designed for corrosive chemical water, used together with CS1528/CS1728FC/CS1737C HF-resistant electrodes to improve measurement stability.

Full measuring range matching electrode specifications

pH: -2~16.00 pH, ORP: -2000~+2000 mV, temperature: -10~150℃, fully covering working conditions of the three electrodes; pH accuracy ±0.01 pH, 24-hour drift ≤0.01 pH.

Differential signal acquisition with strong anti-interference capability

Optimized for weak electrode signals; no reading fluctuation under strong electromagnetic interference from variable frequency motors and pipelines, suitable for long-term online operation.

Automatic temperature compensation compatible with all temperature sensors

Supports identification of NTC10K / NTC2.2K / PT100 / PT1000, automatically correcting pH measurement errors caused by temperature changes. All temperature-compensated electrode models are directly compatible.

Multi-output linkage for automatic control

3 relay outputs for linkage with dosing pumps / valves; dual 4-20mA + RS485 MODBUS communication to connect PLC/DCS. Large display synchronously shows pH, temperature, current and historical curves, with password lock to prevent misoperation.

Industrial protection and diverse installation methods

IP65 protection grade; panel, wall-mounted and pipeline installation available. Supports AC/DC dual power supply, suitable for humid and corrosive chemical workshops.

3. Core Anti-Corrosion Technology: Double Junction Reference System

Fluoride ions in hydrofluoric acid easily corrode ordinary single-junction electrodes and cause abnormal readings. CS1528 and CS1728FC are equipped with standard double junction structures; CS1737C adopts PTFE liquid junction to meet protection requirements under ultra-high HF concentrations.

Double-layer electrolyte blocks fluoride ions and suspended solids from entering the inner reference chamber, extending electrode service life by 2~3 times and reducing calibration frequency.
Stable Ag/AgCl reference system delivers steady output signals, ensuring stable readings on T6000.
Two types of liquid junctions for selection:

PTFE liquid junction (CS1528FC/CS1728FC/CS1737C): For wastewater with high suspended solids and high HF concentration, resistant to crystallization and blockage;
Porous ceramic liquid junction (CS1528C/CT): For high-purity cleaning water with faster ion conduction.

4. Electrode Housing Selection for Multi-Site Installation with Transmitter

Three differentiated electrode structures support full-scenario deployment when matched with T6000.

CS1528 Glass Series (PG13.5 thread)

Fluorine-resistant high-borosilicate glass, Φ12 mm, total length 165 mm. Suitable for flow cells and small reactors, matched with wall-mounted T6000. Available in conventional 0\100℃ version and high-temperature 0\130℃ version; temperature-compensated models support direct temperature measurement to the transmitter.

CS1728FC Plastic Series (G3/4 + NPT3/4 dual thread)

PP+GF glass fiber reinforced impact-resistant housing, total length 184 mm, Φ27 mm. Suitable for large pipelines and outdoor immersion installation, matched with pipeline-mounted T6000. Pressure resistance 0~0.6 MPa, applicable to flue gas desulfurization and wastewater stations with HF ≤ 4000 ppm.

CS1737C Antimony Plastic Electrode (G3/4 upper thread + NPT3/4 lower thread)

PP+GF housing, antimony sensing core, total length 170 mm. Pressure resistance 0\0.3 MPa, specially applied to ultra-high HF concentration conditions above 4000 ppm, immersion installation in pipelines at 0\80℃. PTFE liquid junction prevents fluorine-induced blockage.

5. Sealing & Pressure Resistance Design for Complete Online Monitoring (0~0.6 MPa)

CS1528 and CS1728FC adopt multi-layer fluororubber sealing, pressure resistance 0\0.6 MPa; CS1737C uses multi-layer fluororubber sealing, pressure resistance 0\0.3 MPa, matching pressure requirements of T6000.

CS1528 / CS1728FC for atmospheric and low-pressure chemical pipelines; CS1737C for low-pressure and atmospheric ultra-high HF conditions.
Standard PG13.5, G3/4 and NPT3/4 threads; universal mounting brackets enable direct replacement of old equipment.
Split cable design: only the probe needs replacement if damaged, and the T6000 transmitter can be reused to cut consumable costs.

6. Complete System Selection Guide

Immersion in pipelines ≤80℃, impact resistance, HF ≤4000 ppm: T6000 + CS1728FC plastic electrode
Flow cell / laboratory conditions 0~100℃, HF ≤4000 ppm: Wall-mounted T6000 + CS1528FC/FCT
High-temperature reactors 0~130℃, HF ≤4000 ppm: T6000 + CS1528C/CS1528CT
Ultra-high HF concentration＞4000 ppm, 0~80℃: T6000 + CS1737C antimony pH electrode
HF＞2000 ppm with high suspended solids: T6000 equipped with electrodes with PTFE liquid junction (CS1728FC/CS1737C)
Requiring automatic temperature compensation: Select electrodes with temperature sensor, activate ATC function on T6000
Remote central control monitoring: Enable RS485 on T6000, optional 10~20 m long cables
Automatic acid & alkali dosing: Standard T6000, activate 3 relay outputs

7. Core Advantages of Complete Manufacturer Solution

Chunye Technology independently develops both electrodes and transmitters, eliminating compatibility risks for complete sets.

Self-developed fluorine-resistant glass membrane / antimony sensing electrodes and differential transmitter algorithm with high signal matching.
Standardized parameters for CS1528/CS1728FC/CS1737C, simple selection for complete orders.
Each unit calibrated before delivery with complete test reports provided.
One-stop technical support: full assistance including selection, wiring, calibration and troubleshooting.

For HF monitoring in photovoltaic, fluorochemical, semiconductor and environmental fluorine-containing wastewater industries, the complete monitoring system consisting of Chunye T6000 pH/ORP transmitter and CS1528/CS1728FC/CS1737C HF-resistant electrodes relies on four core technologies: fluorine-resistant glass membrane / antimony anti-corrosion sensing, double junction protection, differential anti-interference transmitter algorithm and multi-specification housings. It covers high-temperature, low-pressure and ultra-high HF concentration working conditions up to over 4000 ppm within 0~130℃, realizing fully automatic pH control. As a cost-effective domestic complete monitoring solution, customized selection schemes can be obtained by contacting the manufacturer.