Back To Top
Rosemount™ 398/398VP pH/ORP Sensors
The chemical-resistant construction of Tefzel®, titanium, and the patented TUpH™ reference junction makes Models 398 and 398R the ideal sensors for measuring pH in harsh process liquids.
Use Models 398 and 398R to measure pH in sour water strippers, in pulp bleaching towers that use chlorine dioxide, and in process streams containing a variety of organic solvents.
Rosemount™ 398/398VP pH/ORP Sensors


Measurement Range
pH: 0 to 14
ORP: -1500 to +1500 mV
Ambient Temperature
250 psig (1825 kPa) at 212°F (100°C)


  • SUPERIOR CHEMICAL RESISTANCE allowing sensors to withstand applications containing chlorine dioxide and a wide variety of organic solvents and oxidizing agents
  • MINIMUM SENSOR MAINTENANCE due to TUpH reference technology which ensures long life in coating, fouling, and poisoning processes
  • MAXIMUM SENSOR LIFE due to helical reference pathway which hinders reference poisoning and cracking resistant glass