The high alarm value cannot be set closer than 1% from the low alarm value due to ASTM specifications. For example, if the low alarm is set at 50%, the system will not accept a high alarm setting less than 51%. Setting the high alarm to 100% turns off or deactivates the high alarm.
4)When the high alarm value is set, press the HIGH SET key again to accept the high alarm setting and return to normal operation.
Note: To automatically set the high alarm to 50% without scrolling the display, hold the HIGH SET key down and then press the ↓ arrow key when the "HIGH" icon is flashing. To automatically turn off the high alarm or set it to 100%, hold the HIGH SET key down and then press the ↑ arrow key when the "HIGH" icon is flashing.
3.2 Basic Operation
To check the oxygen concentration of a sample gas:
1)Place the external probe in the sample gas stream. When using a standard "T" adapter, make sure the sensor is mounted in the adapter with the flow diverter pointing downward. This will prevent moisture from draining into the sensor membrane.
Note: It is important that a tight fit exists between the probe and the "T" adapter.
2)Initiate flow of the sample gas to the sensor.
3)Using the ON/OFF key, make sure the unit is in the power on mode.
4)Allow the oxygen reading to stabilize. This will normally take about 30 seconds or more.
3.3 Alarm Conditions
In the event of either a low alarm or high alarm condition, the corresponding LED will begin to flash, accompanied by the alarm beeper. Pressing the SILENT key will deactivate the buzzer but the LED and the alarm value digits on the display will continue to flash until the alarm condition has been rectified. If the alarm condition still exists 120 seconds after silencing the alarm beeper, the beeper will start to sound again.
A low alarm condition will remain until the actual concentration is .1% higher than the low alarm setting. A high alarm condition will remain until the the actual concentration is .1% lower than the high alarm setting.
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