ANALOX 1371 MK 2 SURVEYOR CARBON DIOXIDE MONITOR
1371-810-03 User Manual, August 2007
1017
4
OPERATION
4.1
ALARM SETPOINTS
4.1.1 The Instrument incorporates two completely independent alarm circuits, which may be adjusted
by the user, to any point within the full range of the instrument. Both alarm circuits are
configured to operate when the measured gas concentration Exceeds the setpoint - ie they are High
going alarms.
4.1.2 When an alarm condition occurs, the appropriate Red LED (HI or LO) will start to flash, the
internal Audible device will sound and the associated relay will change state. The Audible alarm
may be silenced by pressing the 'MUTE' button, located just under the lower edge of the main
panel. This action also changes the LED from flashing to a steady illuminated state. The relay and
LED will remain in this condition, until the measured concentration falls below the alarm
setpoint, at which time, the relay will revert to its normal state and the LED will be turned off.
4.1.3 Adjustment of the setpoints is a simple procedure. Locate the switch marked 'HI - LO' in the
'ALARM ADJUST' section of the front panel. This device is normally spring biassed to its central
position. To read the present setpoint for the LO alarm, press the switch to the right - the setpoint is
then shown on the display. To read the present setpoint for the HI alarm, press the switch to the left
- the setpoint is then shown on the display. To adjust the setpoint, hold the switch in the appropriate
position and using the trimming tool provided, or a small terminal screwdriver, rotate the
appropriate trimmer , 'HI' or 'LO' until the desired setpoint is indicated on the Display.
Clockwise rotation increases the setpoint value. Release the switch and repeat for the other alarm
if required.
