Environment And Oxygen Sensor Readings; Pressure Changes; Specifications - MSA Sirius Operating Manual

Tetrahydrofuran
Toluene
COMBUSTIBLE GAS
Vinyl Acetate
VM&P Naptha
O-Xylene
RESPONSE NOTES:
1. The compounds may reduce the sensitivity of the combustible gas
sensor by poisoning or inhibiting the catalytic action.
2. These compounds may reduce the sensitivity of the combustible
gas sensor by polymerizing on the catalytic surface.
3. For an instrument calibrated on Pentane,multiply the displayed
%LEL value by the conversion factor above to get the true %LEL.
4. These conversion factors should be used only if the combustible
gas is known.
5. These conversion factors are typical for a Sirius Multigas Detector.
Individual units may vary by +25% from these values
Table 7-5. OXYGEN - Typical Performance Specifications
RANGE 0 to 25% O 2
RESOLUTION 0.1% O 2
REPRODUCIBILITY** 0.7% O 2 , for 0 to 25% O 2
RESPONSE TIME 90% of final reading
*See TABLE 7-2 NOTE
**See TABLE 7-10 NOTE

Environment and Oxygen Sensor Readings

A number of environmental factors may affect the oxygen sensor
readings, including changes in pressure, humidity and temperature.
Pressure and humidity changes affect the amount of oxygen actually
present in the atmosphere.

Pressure Changes

If pressure changes rapidly (e.g., stepping through airlock) the oxygen
7-4
0.9
1.2
MULTIPLY % LEL READING BY
0.9
1.6
1.2
30 seconds with sample line and probe
(normal temperature range*)
3 minutes with sample line and probe
(extended temperature range*)