MSA PrimaX I Operating Manual page 8

Safety Regulations
maintenance instructions or by anyone other than an authorised MSA service
personnel, could cause the product to fail to perform as designed.
- The device is designed for applications in hazardous areas under atmospheric
conditions.
- For correct measurements, the combustible gas sensors require an oxygen
concentration greater than 10 Vol%. Oxygen enriched atmospheres, greater
then 21 Vol%, can affect the measurement and the electrical safety of the de-
vice.
- The response time of the device will be increased by significant dust deposits
on the Sensor. Checks for dust deposits must be done at regular intervals.
- Catalytic combustible gas sensors may produce low or zero response to com-
bustible gas after exposure to substances as Silicon, Silane, Silicate, Halide
and compounds containing Fluorine, Chlorine, Iodine or Bromine.
- Catalytic sensor: After exposure of gas above the measuring range, the sensor
has to be immediately calibrated / adjusted, independent of the calibration in-
terval. In the case of an adjustment the sensitivity of the sensor has to be re-
checked again after 24 hours.
- In case of very high flammable concentrations >100%LEL the device is able to
lock all outputs [LOC]. This function shall be used for standalone applications
according to ATEX requirements.
- Catalytic sensor: If the PrimaX is operated in combination with a control unit and
[LOC] is deactivated on the PrimaX, the control unit has to ensure the latching
after the measuring range was exceeded.
- Catalytic sensor: Before a reset of an over range [LOC] indication is done it shall
be verified that the gas concentration is below full scale.
- Toxic gases: If the measuring range is exceeded, sensor life time can be re-
duced or the sensor might need a recovery phase.
- Used sensors have to be disposed of in an environmentally compatible way.
- At signal underrange between -1.25 % and -10 % of the measuring range the
4 - 20 mA output is set to 3,8 mA. At signal underrange of more than -10 % of
the measuring range the 4 - 20 mA output is set to the error state (2 mA). To
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PrimaX
MSA
GB