e)
After AIR CAL., set the instruments so that it can monitor objective gas, and press PUMP key. The color of the
display reverses while the pump is operating. Indication while the pump operating is not the result of
monitoring.
f)
Press PUMP key and stop the pump after indication become stable, and read the indication.
The indication under the condition that the pump and sample gas flow have stopped is the monitoring result.
CAUTION:
Press AIR CAL key after confirming there is enough fresh air in the chamber. Otherwise,
correct measurement cannot be performed.
* NOTE:
If the [AIR] is selected as the base gas, the indication shows zero when the AIR CAL key is
pressed. However, If the [N2] or other gases except [AIR] is selected as the base gas, the
indication does not show zero, but other values determined based on the combination of
the measuring gas and the base gas. This is caused by sampling the gas which is not on
target. (In this case, it is air.) Do not think it broken. Once the instrument samples the
target gas, it shows a correct reading. Depending on the combination of the measuring gas
and the base gas, AIR CAL value may be negative value (minus value). For further
information, refer to the measuring gas specification.
CAUTION:
FI-21 performs best when both Gas Chamber and Reference Chamber are at the
atmospheric pressure (101.3kPa). While the measuring gas is being sampled, the pressure
in the Gas Chamber becomes slightly different from the atmospheric pressure, and the
analyzer does not show the correct reading. Read the indication after the gas flow stops.
* NOTE:
FI-21 measures the gas best when both Gas Chamber and Reference Chamber are at
101.3kPa. If precise measurement is required, perform the pressure correction by the
following method.