YOKOGAWA MG8G, Руководство пользователя, Страница: 52 / 63

<11. INSPECTION AND MAINTENANCE>
11-1
IM 11P03A03-01E 6th Edition : Jan. 26, 2022-00
11. INSPECTION AND MAINTENANCE
This chapter describes the inspection and maintenance procedures to ensure optimum
performance of the instrument and to keep it in good operating condition.
11.1 Checking the Auxiliary Gas
Check that the auxiliary gas is supplied at the specified pressure. When the gas is supplied from
a gas cylinder, check the pressure gauge attached to the cylinder. If the pressure is low, replace
the gas cylinder. The primary pressure of the supplied pressure regulator for supplying auxiliary
gas must be at least 300 kPa. When the auxiliary gas pressure is readjusted, zero and span
calibrations should be conducted.
CAUTION
After the gas cylinder is replaced, zero and span calibrations should be conducted. If air is
trapped in the auxiliary gas line during replacement, the reading will fluctuate and it will take
long time for the reading to stabilize. After the reading has stabilized completely, perform the
calibrations.
11.2 Checking the Sample Gas
Check the flow rate of the sample gas on a timely basis.
11.3 Precautions When Stopping and Restarting
the Operation
The most common failure or trouble occurs when stopping or restarting the operation. Extreme
care should be taken.
(1) When sample gas contains corrosive components, turn off the sample gas flow with the
auxiliary gas being supplied. After turning off the sample gas flow, allow nitrogen gas or
instrument air to flow to purge the sample gas line.
(2) If possible, it is recommended that the auxiliary gas be allowed to flow while the operation is
suspended..
(3) Before restarting the operation, check the sample gas line for moisture due to condensation.
If moisture is present, remove the sample gas line from the instrument and allow instrument
air to flow to purge the pipe completely. Moisture in the sensor unit may result in a failure,
and in the worst case, the instrument will need to be serviced at the factory.
11.4 Fuse Replacement
Two fuses are installed for live and neutral, respectively, in the power unit in the instrument. If the
fuse blows, replace it using the following procedure.
(1) Before replacement, turn off power to the instrument.
(2) Open the instrument cover. Pull the fuse out from the fuse holder which is located near the
power switch as shown in Figure 11.1. Turn the cap counterclockwise until it stops using a
flat head screwdriver of the appropriate size. Pull out the cap together with the fuse.