ENMET MEDAIR 2200 - Manual (Page 13)

M ED A IR 2200 ENMET Corporation
10
4.3 Alarm Latching or Differential Settings
An instrument is shipped with the alarms in the latching mode. The alarms may be independently configured in the
non-latching mode or differential setting by use of the maintenance menu.
See Section 5.3.3, for setting alarm 1 and alarm 2.
Standard Setting
I N THE LATCHING MODE : at the cessation of the condition which causes an alarm, the alarm indications do not
cease, and the alarm relay contacts do not revert to the non-alarm state, until the AUDIO DEFEAT / ALARM
ACKNOWLEDGE switch is pressed. An alarm can also be acknowledged by pressing the switch during the alarm
condition; then at the cessation of the alarm condition, alarm indications cease and alarm relays revert to the non-
alarm state. After an alarm is acknowledged, alarms in the latching configuration are re-armed to latch at the next
alarm condition.
I N THE NON - LATCHING MODE : at the cessation of the condition that causes an alarm, the alarm indications
automatically cease, and the alarm relay contacts revert to the non-alarm state.
Differential Setting
The Alarm 1 differential value is the delay of the M ED A IR 2200 staying in alarm condition until after the measured
reading has returned past the alarm point by the differential value. Example: If the alarm point is
Λ
10 and the
differential is 2, the M ED A IR 2200 will go into alarm at 10 and stay in alarm until the reading has dropped below
8.
4.4 Audio Defeat
Pressing the AUDIO DEFEAT / ALARM ACKNOWLEDGE switch during an alarm temporarily silences the audio alarm.
Relays and alarm LEDs continue to function, in the alarm state, during an alarm condition. As long as the alarm
condition persists, the audio alarm will “chirp” every 20 seconds.
If after 15 minutes the alarm condition continues the audio alarm will reactivate at full intensity.
If any other alarm condition occurs while the audio alarm has been silenced it will force the audio alarm to
reactivate immediately.
4.5 Display
In clean air a display is shown in Figure 4 . This position of the display is termed the "operational display". As
explained below, the display can be used to view other information by using the OPTION and SELECT switches.
Concentrations of CO and CO
2
are given in PPM (parts per million parts of air). Dew point is given in degrees
Fahrenheit at 55 PSIG ; this can be changed to degrees Centigrade by pressing the SELECT switch. Oxygen
concentration is given in percent by volume.
When sample flow is reduced below a limit, the bottom line of the display flashes “Low Flow Alarm”.