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Model 546 pH/ORP Sensor

546 pH/ORP Sensor

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Axial Ion Path® Reference
  • Patented design increases sensor life, accuracy and reliability
  • High resistance to poison: Reduced calibration offset error
  • Large surface area reference junction eliminates plugging issues
  • Eliminates error due to fluctuating pressure
  • No exotic gel or polymer electrolyte which may be incompatible with the process

The versatile Model 546 is suitable for in-line sample stream applications using the 3/4 inch NPT process connection. A similar 3/4 inch NPT connection on the rear of the sensor is used to mount the sensor in submersible and high pressure hot tap installations. With tip lengths from 0.5 to 5.0 inches the 546 sensor can fit through extended pipe nipples and flanges to reach into the process and provide optimum pH/ORP measurement.

Pressure/Temperature Ratings


Installation Type
 3/4" In-line or Submersible*  High Pressure Hot Tap
 Kynar (red / blue**)          150 PSIG @ 158°F (70°C)
 40 PSIG @ 266°F (130°C)
 300 PSIG @ 176°F (80°C)
 40 PSIG @ 266°F (130°C)
 Peek (tan)  150 PSIG @ 158°F (70°C)
 40 PSIG @ 266°F (130°C)
 300 PSIG @ 176°F (80°C)
 40 PSIG @ 266°F (130°C)

 *When using jet cleaner please consult accessories documentation for pressure ratings.
 **Blue Kynar (used with solution ground) not recommended in high pressure hot tap applications.

Insertion Depth

The depth that pH / ORP sensor protrudes into the pipeline can greatly affect the measurement. Applications where the sensor tip is recessed can lead to coating and slow response. In high particulate applications abrasion of the electrode can be a concern.

A typical installation goal is to get the sensor tip at least 1/4" (6mm) into the stream. At this depth coating issues lessen and response improves due to flow velocity. 546, 551 and 547 sensors offer a variety of insertion depths. Here are some guidelines.

546 In-Line Installation Examples

Installation Methods

Submersible Applications
Isolation Ball-Valve "Hot-Tap" Applications
In-Line Applications (Threaded)
In-Line Flange Applications