V100 (2019-11)
Doc. Ref. XGC-320-100119
33
Other considerations when using gases other than N
2
/
air
Flammable or explosive gases
WARNING!
Ideal Vacuum Products convection gauges
are neither intrinsically safe nor explosion proof and are not in-
tended for use in the presence of flammable or explosive gases
or vapors.
Under normal conditions the voltages and currents in Ideal
Vacuum Products convection gauges are too low to cause igni-
tion of flammable gases. However, under certain failure condi-
tions, sufficient energy could be generated to cause flammable
vapors or gases to ignite or explode. Thermal conductivity
gauges like the Ideal Vacuum Products convection gauges are
not recommended for use with flammable or explosive gases.
Moisture / water vapor
In some processes (lyophilization, for example) the gas composi-
tion may not change significantly, except for moisture content.
Water vapor can significantly change the response of a thermal
gauge and correction should be made, as you would for any
other gas.
Other contaminants
If your gases condense, coat, or corrode the sensor, the gauge
calibration and response to different gases will change. Gener-
ally, if the gauge can be "calibrated" ("zero" and "span" settings),
these changes are small enough to be ignored. If you can't set
zero and span, the gauge should be replaced or return to factory
for evaluation and possible cleaning.