Ag/AgCl Reference

High-Temperature and High-Pressure Zirconia-Based pH Electrodes 

ZrO₂-Based High-Temperature and High-Pressure pH electrodes are divided into three types (A, B, and C).

Types A and B pH electrodes have a compression fitting and an insertion tube. Type A has an NPT fitting with a metal seal that will be locked to the insertion tube after first use (insertion depth one-time adjustable only). Type B has an NPT fitting with a soft seal that can be reposition on the insertion tube after each use (insertion depth fully adjustable).  The NPT fittings for Types A and B designs are sold separately.  

Type C pH electrode has a thread fitting. If the NPT size is 1/4" or larger, a thin-walled protection tube may be provided . Type C design is ultra compact and may be used in autoclaves that have smaller access ports (1/8" or 1/4" NPT). But the insertion depth for Type C is fixed at factory (non adjustable). 

Specifications:

  Pressure: 

     Ambient to 2000 psi (13 MPa) (Higher pressure models available)

  Temperature:

    130oC (266oF) to 343oC (650oF) 

    for continuous use

  Tube/Fitting Materials:

    316L Stainless steel (standard), Ti and

    C-276 available

  Electrode Materials:

    Cu/Cu₂O (standard), Others available

  Seals :

    Queon^TM . Double seal design  

High-Temperature and High-Pressure Pressure Zirconia-Based pH Probes Selection Guide

Order Code	Connection Type and Size*	Tread Fitting Options	Upper Design Pressure PSI (atm)	Sealability Helium Leakage+ cc/sec	Temperature Range oF (oC)
Zirconia-Based pH Electrodes with Compression Fitting
pH -Zr-b-Tube500*	1/2" Tube	N/A (No fitting)	2000(136)+	<2x10-8	266(130) - 650(343)
pH -Zr-b-Tube500-NPT375A	3/8”NPT on 1/2" Tube	One-Time Adjustable	2000(136)+	<2x10-8	266(130) - 650(343)
pH -Zr-b-Tube500-NPT500A	1/2”NPT on 1/2" Tube	One-Time Adjustable	2000(136)+	<2x10-8	266(130)- 650(343)
pH -Zr-b-Tube500-NPT500B	1/2”NPT movable on 1/2" Tube	fully Adjustable	2000(136)+	<2x10-8	266(130) - 650(343)
pH -Zr-b-Tube500-NPT750B	3/4”NPT movable on 1/2" Tube	fully Adjustable	2000(136)+	<2x10-8	266(130) - 650(343)
Zirconia-Based pH Electrodes with Thread Fitting
pH -Zr-b-NPT125C*	1/8" NPT	Non-Adjustable	2000(136)+	<2x10-8	266(130) - 650(343)
pH -Zr-b-NPT250C*	1/4" NPT	Non-Adjustable	2000(136)+	<2x10-8	266(130) - 650(343)
pH -Zr-b-NPT500C	1/2" NPT	Non-Adjustable	2000(136)+	<2x10-8	266(130) - 650(343)

* No protection tube and extra cares are needed during handling because Zr₂O tube is fragile.

⁺ Higher pressure models are available.