Operation – RKI Instruments GasWatch 1 User Manual
Page 9
GasWatch Instruction Manual (Two-Gas)
Operation • 5
Operation
This section describes the GasWatch in normal operation. This section also describes
procedures to display peak readings, and set the alarm points and time and date.
Normal Operation
The GasWatch continuously monitors the atmosphere and displays the concentrations
present of one of the target gases.
•
Press the DISP button to display the second target gas.
•
Press the POWER/MODE button to turn on the display back light in dimly-lit areas.
Displaying Peak Readings
NOTE:
For CO and H
2
S, peak readings represent the highest reading. For O
2
, peak
readings represent the lowest reading. The GasWatch displays peak readings for
the target gas that is currently displayed on the normal screen.
1.
From the normal screen, press the MODE button. The back light turns on.
2.
Press the MODE button again. The peak reading displays. This is the peak reading
since the last time the GasWatch was turned on.
NOTE:
The GasWatch does not display STEL or TWA readings for the oxygen sensor.
3.
Press the MODE button again. The STEL reading displays.
The STEL (short term exposure limit) reading is the average gas reading over the past
15 minutes.
4.
Press the MODE button again. The TWA reading displays.
The TWA (time weighted average) reading is the average gas reading over the past
8 hours. If the GasWatch has been on less than 8 hours, it assumes the reading has
been 0 during the period the GasWatch was turned off.
5.
Press the MODE button again to return to the normal screen. The back light is off.
Adjusting the Alarm Points
NOTE:
When adjusting alarms points, the AIR button increases the setting, and the DISP
button decreases the setting.
1.
Verify that the GasWatch is turned off.
Only the time of day is displayed when the GasWatch is off. To turn off the GasWatch,
press the POWER button until only the time of day is displayed (approximately 5
seconds).
2.
Press the MODE and AIR buttons simultaneously.
3.
Release the AIR button when the GasWatch displays all display elements
(approximately 1 second).
The GasWatch beeps, then the decreasing oxygen alarm point displays.