PureAire Monitoring Systems, Inc.
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This is the gas concentration at which the instrument’s audio alarm will be activated.
To change the displayed value, push the joystick to the right to display the Audio
alarm setting. The display will indicate a value between 0.0ppm and full scale of the
monitor. Pushing the joystick up increases the value and pushing the joystick down
decreases the value.
NOTE: The audio can be set into only one alarm level. You can choose between
alarm level 1 or alarm level 2 or set a completely different setting.
After entering the audio alarm threshold value, pushing the joystick left, the display will
default back to the Set Audio Alarm Relay Threshold menu. The display will scroll the
following:
5.5.9 Set Alarm Hysteresis
PureAire’s Universal Gas Detector may be used as a control system. When used to
regulate gas levels the need of a dead band, “hysteresis” may be required for the alarm
relays. This menu will permit the setting of the alarm hysteresis to a desired gas
concentration. When using hysteresis, the alarm set point now becomes an average
alarm setting for an action to occur. When adding the hysteresis value to the alarm set
point, this then defines the alarm and dead band for an action to occur.
For example, if you require a fan to turn on at a 5ppm level and to turn off at a 4.5ppm
level, you would set the Alarm Threshold at 5ppm and set the hysteresis value at
0.5ppm (Average Alarm set point = 5.0ppm - Hysteresis 0.5ppm = 4.5ppm Fan Off)
To access this menu push the joystick down to display the
Set Alarm Hysteresis
menu.
This will scroll on the digital display.
To change these values, push the joystick right to display the
Set Alarm 1 Hysteresis.
5ppm
0.0ppm
..Set Audio Alarm Threshold…
0.0ppm
..Set Alarm Hysteresis…
0.0ppm
..Set Alarm 1 Hysteresis…
0.0ppm
