Australian Oxytrol Systems

HT Probe

HT Probe - for use over 1000°C

  HT probe - overview

The type HT probe is suitable for use at temperatures over 1000°C.

All of the components exposed to the high temperature gases are ceramic or platinum, for optimum corrosion resistance. It is of robust construction, with an alumina ceramic sheath to protect the sensing element.

ModelRange (°C)SheathDiameter (mm)Thermocouple
HT700 - 1700ceramic15 O.D. x 11 I.D.type R


The probe can be installed anywhere in the kiln or furnace, provided that the temperature at the tip is between 700°C and 1700°C. The probe will measure the oxygen concentration at the probe tip.

The port for installation should be sealed sufficiently to avoid atmospheric air from flowing inwards and causing a local variation in the oxygen concentration.

The probe can be used at any orientation for temperatures up to 1100°C, but should hang vertically if used at higher temperatures.


The probe head should be maintained at a temperature less than 60°C.

Clean respirable reference air at a rate of 10 cm3/min must be supplied to the connection provided on the probe head.

The electrical connections are:

Pin 1Pt/Pt13%Rh leg of R-type thermocouple
Pin 2Pt leg of R-type thermocouple
Pin 3Oxygen sensor internal conductor
Pin 4Oxygen sensor external conductor


The oxygen signal is according to the Nernst equation

pO2 = 0.209 exp(-46.42E/T)


pO2 = oxygen partial pressure in atmospheres
E = oxygen signal in mV
T = temperature in Kelvin


There are no user serviceable parts inside the probe. If the external platinum conductor is broken, it can normally be rejoined without loss of accuracy.

Ordering & Information

For further information or a price quotation, please enquire, specifying length required, to Australian Oxytrol Systems or use the online Enquiry Form

Probes are normally ready for despatch by international air freight within one week of order.

Please note that all prices are in Australian dollars. Please see the Commonwealth Bank currency converter to calculate the price in your currency.

  HT probe - view of electrical and air connections