RKI Instruments GD-K77D - Manual (Page 36)

31 • Maintenance Model GD-K77D Operator’s Manual
Maintenance
This section covers maintenance, calibration, and storage.
There are two levels of maintenance:
• Monthly maintenance requires that you check the proper functioning of the flowmeter,
power light, LED display, and dust filter.
• Semiannual maintenance requires that you perform a zero adjustment, do an alarm
test, check the gas inlet and outlet, and replace the sensor or dust filter if required.
Monthly Maintenance
• Flowmeter. Check the flowmeter to make sure the flow ball is between the two
red flow lines. The flow rate of the Model GD-K77D is 500cc/min. If the flow ball is
not between the red flow lines, adjust the air flow. When the flow ball is above the
top flow line, press the FLOW ADJ switch down to reduce the flow rate. When the
flow ball is below the bottom flow line, press the FLOW ADJ switch up to increase
the flow rate. When the flow ball drops below the bottom flow line, the Model GD-
K77D cannot accurately detect the target gas.
• PW/TR Light. During normal operation, the PW/TR should be on (i.e., green).
• LED Display. In the absence of a gas leak, the LED display should read 0.00. If
the LED display does not show zero, there may be a gas leak or you may need to
make a zero adjustment to the Model GD-K77D. If you suspect a gas leak, use a
portable gas detector to verify the leak in the monitoring area, then take the
necessary actions to remedy the problem, which may include checking the Model
GD-K77D’s alarm contacts and the alarm system connected to the unit. If a leak is
not detected, perform a zero adjustment on the Model GD-K77D. (See “Zero
Adjustment” under “Maintenance Mode” for more information).
Semiannual Maintenance
• Zero Adjustment. A zero adjustment resets the Model GD-K77D’s gas detecting
system to zero so it can accurately sample the target gas. See “Zero Adjustment”
under “Maintenance Mode” and “Calibration” for more information.
• Gas Tubing. Check the gas tubing connected to the gas inlet and gas exhaust of the
Model GD-K77D. Make sure that the tubing is not bent or damaged.
• Dust Filter. Examine the dust filter and replace it as required. If the flow ball in the
flowmeter drops below the bottom flow line, and increasing the flow rate by pressing
up on the FLOW/ADJ switch does not raise the flow ball, the filter may be clogged and
requires replacement. Also check the flow path to make sure the gas inlet tube is not
bent or damaged.
NOTE: Calibrate the Model GD-K77D every six months. See the Calibration section below.