PH402 Four-Wire pH/ORP Analyzer (DISCONTINUED)

Notice: This product was discontinued on Jan 1, 2004.

PH402 Four-Wire pH/ORP Analyzer

Application Note

pH measurement in brine solutions (for example NaCl solutions as found in electrolysis processes or cheese manufacturing) are difficult and inaccuracy and short sensor life are the key problems in these applications. 

Application Note


In Bioscience company's pH is used at various places including glass lined reactor for product efficiency. One of such measurement of pH in reactor as explained below.

Application Information

Typical example of process is:

Reactor used is GLASS LINED REACTOR and length is 1950mm; and flange size 100mm split flange with 8 holes

PCB (fixing hole center to center) 190mm; flange outer to outer 225mm; flange extension pipe (Nozzle) ID 95mm.

Nature of fluid: Aqueous media
Operating temp & pressure: 30°C temp & atmosphere pressure
Area classification - Example Zone 1 / Zone 2
Nozzle ID: 95mm.


Product Recommendation

Measurement System

Process Liquid Analyzer: 

  • 2-wire FLEXA pH/ORP Analyzer
  • Dual sensor measurement on 2-wire type analyser
  • Indication of sensor wellness


  • 4-wire PH450G pH/ORP Analyzer



  • Easy touchscreen operation
  • Trending display up to 2 weeks
  • Advanced Process Temperature Compensation

Sensor Selection:




  • Best measurement accuracy both in high-alkali processes and in samples with very low conductivity.
  • Sterilizable and autoclavable
  • SINGLE PORE‘s for clog-free contact of electrolyte with measurement medium
  • HAMILTON “H” pH glass
  • Serialized with batch number

Sensor Accessories

5mtrs Cable, Model No.: WU10-V-S-05 ,

Immersion sensor fitting (Customised): 1900mm Length, 4" Flange Connection with 8 holes PCB (fixing hole centre to centre) 190mm;  flange outer to outer 225mm; pipe (Nozzle) ID95mm. MOC : PTFE.

Tangible benefit

More reliable and accurate analysis of pH which helps to improve end product quality.

Note: For additional information on this application contact the local Yokogawa Process Liquid Analyzer Department


The lifetime of a pH sensor has a significant impact on the overall annual costs of a pH measuring loop. Optimizing four key factors will decrease these costs and optimize process control and overall plant efficiency.

Instruction Manuals
Technical Information

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