ENMET SPECTRUM - Manual (Page 9)

SPECTRUM Series ENMET Corporation
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2.1.2 Turn ON and OFF
Turn the instrument ON by pressing the POWER / BACKLIGHT pushbutton for two seconds. For most instruments,
the display should read "0000" or near 20.9 within ten seconds when the instrument is in uncontaminated air.
N OTE : Instruments using biased sensor, stabilization time is extended to 4 minutes. Complete stabilization may take
as long as 1 hour. When instrument is turned on it may display XXXX + . If instrument has been off for an
extended amount of time it may be necessary to “cycle” (turn on and off) the instrument several times. See
Table 1 for identification of biased sensors.
Turn the instrument OFF by pressing and holding the POWER / BACKLIGHT pushbutton for three seconds. The
display flashes "OFF" and then fades out after the pushbutton is released. The instrument can be turned OFF from any
location in the operational or maintenance menus.
2.1.3 Gas Concentration Display and Alarms
The LCD furnishes a numerical display of the target gas concentration from 0000 to the upper limit of the range,
shown in Table 1 on page 17. The display of the target gas concentration is termed the "operational display". If the
target gas concentration exceeds the upper limit of the range, the display is the numerical upper limit and a plus sign,
for example,"0200+", for hydrogen sulfide. When the concentration of the target gas exceeds the alarm set point, the
audio and visual alarms are activated. The gas concentration continues to be displayed during alarm. The alarm point
is adjustable between a lower and upper alarm limit by accessing the maintenance menu; these and the factory setting
of the alarm point are also given in Table 1. A user should have a justifiable application-based reason for setting the
alarm point higher than the factory setting. When the target gas concentration drops below the alarm point, the audio
and visual alarms cease operation. The alarm point setting can be observed on the display by pushing the
OPTION
pushbutton twice.
Some types of gases are difficult to detect in an ambient/static atmosphere. For these types of gases ENMET
recommends using a sampling system similar to ENMET Sample Draw Module 03700-029. See Appendix A Table 2.
For the oxygen SPECTRUM , the zero gas display is 20.9% oxygen, and the two alarm points are at 19.5%
(adjustable) and 23.5% (fixed).
If an alarm concentration is encountered when the display is at a location in the operational menu other than the
operational display, the audio and visual alarms are activated and the alarm cannot be acknowledged.
If the display is left idle at a location other than the operational display for 45 seconds it automatically transfers to the
operational display.
2.1.4 Alarm Acknowledge
When the instrument is in alarm, and the target gas concentration is below the upper alarm limit, the alarm can be
acknowledged by pressing and releasing the
SELECT pushbutton, but only when the instrument is at the operational
display. The acknowledgement causes the temporary cessation of the audio alarm; the red LED continues to be ON.
The audio alarm is OFF for a period of four minutes, after which it is reactivated, if the gas concentration is still above
the alarm point. The alarm can again be acknowledged. However, acknowledgement of the alarm at gas
concentrations above the upper alarm limit does not result in audio alarm cessation, and if the gas concentration rises
above the upper alarm limit during an alarm condition which has been acknowledged, the audio alarm resumes
operation.
The alarms are high energy users. The LED alone uses twice as much energy as the non-alarming instrument.
Prolonged use of the instrument while it is in the alarm condition causes a marked decrease in battery life.
2.1.5 Confidence Beep
During normal operation, with no alarm conditions, the audio and visual alarms are activated once every thirty
seconds.