Using The Sensor With Silicones - Michell Instruments XZR200 User Manual

GOOD MEASUREMENT PRACTICE
4. Reducing Atmospheres
Long time exposure to reducing atmospheres may, in time, impair the catalytic effect
of the Pt-electrodes and has to be avoided. Reducing atmospheres are defi ned as an
atmosphere with very little free oxygen and where combustible gases are present. In
this type of atmosphere oxygen is consumed as the combustible gases are burned.
5. Other
Fine dust (Carbon parts/soot) might cause clogging of the porous stainless steel fi lter
and may have an effect on the response of the sensor to oxygen changes. Heavy shocks
or vibrations may alter sensor properties resulting in the need for a recalibration.
5.2.4

Using the Sensor with Silicones

The XZR200 oxygen sensor, like all other Zirconium Dioxide sensors, will be damaged
by silicon presence in the measurement gas. Vapors (organic silicone compounds) of
RTV rubbers and sealants are widely used in many applications. These materials, which
are often applied as a liquid or gel, still release silicone vapors into the surrounding
atmosphere even after they have cured. When these vapors reach the sensor the
organic part of the compound will be burned at hot sensor parts, leaving behind a very
fi ne silicon-dioxide (SiO
electrodes.
If silicon cannot be avoided in the application we advise using high quality, high
temperature cured materials which do not release silicone vapor when subsequently
heated.
!
16
). This SiO completely blocks the pores and active parts of the
2 2
When installing the sensor do not use any lubricants or grease
which may contain silicon.
XZR200 User's Manual
97337 Issue 4, July 2018