RKI Instruments GasWatch 2 Manual - Manual (Page 12)

7 • Description GasWatch 2 Operator’s Manual
Printed Circuit Boards
The primary function of the GasWatch 2’s two printed circuit boards are to
amplify the current or voltage signal sent to them from the gas sensor,
convert the signal to a meaningful measurement of gas concentration,
display the gas concentration on the LCD, store peak, STEL, and TWA
readings, and activate the alarm circuit if an alarm point has been reached.
They monitor battery level, battery failure, and sensor failure. They also
control the GasWatch 2’s time function and the various operating modes of
the unit.
NOTE: The printed circuit boards contain no user serviceable parts.
Table 2: The Control Buttons of the GasWatch 2
Button Function
POWER/MODE
• Turns the unit on and off.
• Turns the LCD back light on.
• Displays STEL and TWA readings (GW-2H & GW-
2C).
• Displays peak readings (high for GW-2H & GW-2C
and low & high for GW-2X).
• Resets the alarm circuit (gas alarms).
• Enters Calibration Mode with the AIR button.
• Enters Alarm Adjustment Mode with the AIR
button.
• Enters Time Adjustment Mode with the AIR button.
AIR
• Turns the LCD back light on.
• Adjusts LCD readings when a fresh air adjustment
is performed.
• Enters Calibration Mode with the POWER/MODE
button.
• Enters Alarm Adjustment Mode with the POWER/
MODE button.
• Enters Time Adjustment Mode with the POWER/
MODE button.
• Increases settings when the unit is in Alarm
Adjustment Mode, Time Adjustment Mode, or
Calibration Mode.