PH/ORP Instrumentation Classification

Overview of PH/ORP Instrumentation Classification

E+H's PH/ORP product system is divided into four major categories by core functional modules: transmitters responsible for signal processing, electrodes responsible for detection, cables responsible for signal transmission, and cleaning and calibration systems responsible for maintenance assistance. Each product category has clear functions and fixed pairing logic, together forming a complete PH/ORP measurement solution.

I. PH/ORP Transmitters

Transmitters convert the analog or digital signals collected by electrodes into standard outputs such as 4-20mA+HART, while also providing data display, fault diagnosis, and calibration management. They are the key hub connecting electrodes with PLC/DCS control systems. According to functional complexity, they are divided into basic general-purpose and advanced functional types.

1. Basic General-Purpose Type

  • Core Models: CPM223, CPM253
  • Performance Features: Modular design, supporting panel-mounted or field installation; software switching between PH and ORP measurement modes; two-line display of measured value and temperature; menu-driven operation supporting six languages; CAL key for quick two-point calibration; equipped with overvoltage protection, calibration plausibility check, and custom alarm contacts.
  • Applicable Scenarios: Conventional industrial scenarios such as water treatment, chemical neutralization tanks, power plant flue gas scrubbing, and cooling water treatment; suitable for monitoring points that are cost-sensitive and have no complex control requirements.
  • Cost Level: CPM223 approximately 6,613-9,449 RMB, CPM253 approximately 7,126-10,689 RMB, with outstanding cost-effectiveness.

2. Advanced Functional Type

  • Core Model: CPM153
  • Performance Features: Four-wire transmitter, supporting electrode status monitoring (SCC), impedance (SCS), and measurement signal (PCS); data logging and automatic buffer recognition; one-button calibration; integrated "Chemoclean" automatic cleaning; support for integral and derivative measurement; modular expansion for dual-loop measurement and enhanced controllers; output relays compliant with NAMUR standards.
  • Applicable Scenarios: High-precision process control scenarios such as precise monitoring of chemical reactors, compliance measurement in food and pharmaceuticals, and chip manufacturing.
  • Cost Level: Approximately 12,827-17,815 RMB per unit, suitable for applications with high requirements for performance and scalability.

II. PH/ORP Electrodes

Electrodes directly contact the medium and collect signals; their performance determines measurement accuracy and stability. They are subdivided by three dimensions: measurement type, signal type, and material characteristics. Different types differ significantly in accuracy, interference resistance, medium compatibility, and cost.

1. Pure PH Electrodes

Measure only PH value; divided by signal type into digital and analog, and by material into non-glass and conventional glass.

(1) Digital PH Electrodes

  • Core Models: CPS491D, CPS171D, CPS341D, CPS411D, CPS71D, CPS91D, CPS41D, CPS31D, CPF81D, CPS81D
  • Performance Features: Memosens digital technology, strong interference resistance, supporting long-distance transmission (some up to 1000 meters); predictive maintenance and laboratory calibration; convenient field replacement; accuracy ±0.01-0.02 pH, response ≤2 seconds.
  • Applicable Scenarios: Chemical workshops with high electromagnetic interference, long-distance wiring water treatment systems, and continuous production scenarios with frequent maintenance.
  • Cost Level: 5,701-10,689 RMB per unit, suitable for scenarios with requirements for signal stability and maintenance convenience.

(2) Analog PH Electrodes

  • Core Models: CPS471, CPF201, CPS441, CPS491, CPS91, CPS71, CPS31, CPS11, CPS41, CPF81, CPF81E
  • Performance Features: Output mV-level analog signal, accuracy ±0.02-0.1 pH, response ≤3 seconds; simple structure, requires pairing with a transmitter; relatively weak interference resistance, suitable for short-distance transmission ≤50 meters; some models have stable pressure at 16 bar and temperature resistance up to 135°C.
  • Applicable Scenarios: Municipal wastewater, cooling water treatment, ordinary chemical storage tanks, and other conventional interference environments.
  • Cost Level: 3,563-6,413 RMB per unit, with outstanding cost-effectiveness.

(3) Non-Glass PH Electrodes

  • Core Models: CPS77D, CPS47D, CPS471D, CPS77E, CPS97E, CPS47E, CPS341D, CPS441, CPS471
  • Performance Features: ISFET and other non-glass sensing materials, wear-resistant, corrosion-resistant, no risk of glass breakage, service life more than 30% longer than conventional glass electrodes; accuracy ±0.02 pH, compatible with media containing solid particles and strong acids/alkalis, some temperature-resistant up to 150°C.
  • Applicable Scenarios: Harsh media such as mining wastewater, strongly corrosive chemical solutions, and food processing liquids containing suspended solids.
  • Cost Level: 4,988-8,551 RMB per unit, suitable for long-term stable measurement in harsh environments.

(4) Conventional Glass PH Electrodes

  • Core Models: CPS11D, CPS11E, CPS12D, CPS12E, CPS41E, CPS71E, CPS31E, CPS61E, CPS97D, CPS91E
  • Performance Features: Special glass sensing, high accuracy (±0.01 pH), fast response (≤1.5 seconds); weak impact resistance, susceptible to hydrofluoric acid corrosion, need to avoid solid particle impact; some models comply with 3A certification.
  • Applicable Scenarios: Clean and low-corrosion scenarios such as pharmaceutical purified water, electronic ultrapure water, and food and beverage clean liquids.
  • Cost Level: 4,275-7,838 RMB per unit, suitable for high-precision, clean medium scenarios.

2. Pure ORP Electrodes

Measure only oxidation-reduction potential; divided by signal type into digital and analog.

(1) Digital ORP Electrodes

  • Core Models: CPS72D, CPS42D, CPF82D, CPS12D, CPS12E (some models)
  • Performance Features: Memosens digital technology, strong interference resistance, supporting long-distance transmission and pre-calibration; measurement range -1000~+1000 mV, accuracy ±2 mV, response ≤3 seconds; some with temperature compensation.
  • Applicable Scenarios: Redox monitoring of electroplating baths, printing and dyeing wastewater treatment, and chemical oxidation reaction process monitoring.
  • Cost Level: 6,057-11,401 RMB per unit, suitable for high stability and accuracy requirements.

(2) Analog ORP Electrodes

  • Core Models: CPS92E, CPS72E, CPS42, CPS12, CPF82, CPF82E, CPS72, CPS92, CPS42E, CPS62E
  • Performance Features: Output mV-level analog signal, range -1000~+1000 mV, accuracy ±5 mV, response ≤5 seconds; simple structure, requires pairing with a transmitter; relatively weak interference resistance, short-distance transmission; some temperature-resistant up to 100°C.
  • Applicable Scenarios: Municipal wastewater disinfection, swimming pool water quality maintenance, and ordinary industrial wastewater treatment.
  • Cost Level: 3,919-6,770 RMB per unit, with outstanding cost-effectiveness.

3. PH/ORP Combination Electrodes

  • Core Models: CPS76E, CPS96E, CPS16E, CPS76D, CPS96D
  • Performance Features: Integrated design, simultaneously outputting PH and ORP dual signals, reducing installation space and wiring costs; digital versions support Memosens technology, analog versions are lower cost; PH accuracy ±0.02 pH, ORP accuracy ±3 mV, response ≤3 seconds.
  • Applicable Scenarios: Chemical reactors, aquaculture water quality management, environmental online monitoring stations, and other scenarios requiring simultaneous dual-parameter monitoring.
  • Cost Level: Digital version 8,551-14,252 RMB per unit, analog version 5,701-9,264 RMB per unit, more economical than purchasing two separate units.

III. PH/ORP Cables

Cables connect electrodes and transmitters and must be selected according to signal type, installation distance, and environmental interference intensity to ensure stable signal transmission.

1. Dedicated Cables for Analog Electrodes

  • Core Features: Shielded twisted-pair structure, reducing electromagnetic interference, suitable for mV-level weak signal transmission, recommended distance ≤50 meters; some models are oil-resistant and weather-resistant.
  • Applicable Scenarios: Paired with analog electrodes such as CPS471 and CPS92E for conventional industrial short-distance wiring.
  • Cost Level: 106.9-213.8 RMB per meter.

2. Dedicated Cables for Digital Electrodes (Memosens Cables)

  • Core Features: Dedicated digital signal transmission line, supporting Memosens protocol, transmission distance up to 1000 meters, resisting strong electromagnetic interference without additional shielding; some models are waterproof and explosion-proof.
  • Applicable Scenarios: Paired with digital electrodes such as CPS491D and CPS72D for long-distance, high-interference environments.
  • Cost Level: 178.1-320.7 RMB per meter.

3. Supplementary Conventional Cable Models

  • CYK10: Conventional PH signal transmission cable, compatible with most analog or digital PH electrodes, suitable for short-distance within 10 meters in conventional environments.
  • CPK9: Stronger interference resistance, suitable for PH signal transmission over 10-50 meters in high electromagnetic interference environments.

IV. Cleaning and Calibration Systems

Used to ensure long-term measurement accuracy of electrodes, reduce manual maintenance costs, and avoid measurement errors caused by medium adhesion or calibration deviation.

1. Automatic Cleaning Systems

  • Core Features: Spray or scraper structure, can automatically start cleaning at scheduled times or according to contamination level; some support chemical cleaning (acid cleaning, alkali cleaning), suitable for stubborn dirt.
  • Applicable Scenarios: Paired with electrodes used in highly contaminated media such as CPS47D and CPS92E, e.g., mining wastewater and food processing wastewater monitoring.
  • Cost Level: 5,701-10,689 RMB per set.

2. Calibration Solutions and Tools

  • Core Features: Provide standard PH buffer solutions (pH4.01, pH7.00, pH10.01) and ORP standard solutions (e.g., +475 mV), suitable for two-point or three-point calibration; supporting tools such as calibration cups and protective sleeves.
  • Applicable Scenarios: Regular calibration and maintenance of all PH/ORP electrodes.
  • Cost Level: Standard buffer solution (500mL/bottle) 213.8-356.3 RMB per bottle, calibration tool set 1,069-2,138 RMB per set.

3. Supplementary Models of Cleaning and Calibration Systems

  • CDC90: Integrates cleaning and calibration dual functions, high degree of automation, suitable for unattended, high-frequency maintenance scenarios such as continuous production chemical plants.
  • CYC: Only has cleaning function, simple structure, lower cost, suitable for scenarios with light contamination and only requiring regular cleaning, such as municipal water treatment plants.

Selection Recommendations and Summary

When selecting PH/ORP instruments, comprehensive consideration should be given to measurement accuracy, environmental interference, medium characteristics, transmission distance, and maintenance costs. Digital Memosens technology has obvious advantages in interference resistance and long-distance transmission, suitable for complex industrial scenarios; analog products are cost-effective and suitable for conventional monitoring. Reasonably pairing transmitters, electrodes, cables, and cleaning and calibration systems can build a stable and reliable PH/ORP measurement solution.