Technical Manual
XNX Universal Transmitter
Section 2 - Installation and Operation
67
Range & Alarms
Warning: XNX Universal Transmitters carrying UL/CSA approvals
that are configured for devices measuring %LEL will not allow
adjustments to the full scale value. The range is fixed at 100%.
The Range & Alarms option applies only to units with
certicationsotherFthanUL/CSA.
Figure 84. Range & Alarms Menu
Set Range (full-scale)
Range is sensor dependent. The Set Range option allows the
full-scale range to be set for the sensor which is attached to the
transmitter. The full-scale range is based on the capability of the
sensor.TheselectablerangeforECsensorsisdenedinthe
Selectable Range column of the table in Section 6.3.2. The selectable
rangeforcatalyticbeadsensorsisdenedintheSelectableRange
column of the table in Section 6.3.5.
Figure 85. Range Option
When the Range option is highlighted, use the switches
to decrement or increment the value. Use
✓
to accept the
displayedvalueandmovetothenexteld.Whenalleldshave
been updated, use the switch to highlight ü on the right side
of the display. Use
✓
to accept the changes.
✓
Figure 86. Setting the Range Value
When complete, the display will return to the Range Option
screen.
Set Alarm Values
Set Alarm Values allows the values for Alarm Direction and Alarm
Limits for both Alarm 1 and Alarm 2 to be set.
Caution: Alarm 1 and Alarm 2 values must be less than the Upper
Limit value.
Use Alarm Direction to establish whether the alarm is to be
triggered by rising or falling gas concentrations. Alarms for
most target gases are triggered by rising concentration levels
butcertaingases;e.g.,oxygen,canbemeasuredfordepletion
levels.WhentheXNXtransmitterisconguredwithmVor
OPTIMA sensors and the meaurement units are LEL, the alarm
level setting is limited to 60%LEL.
If the concentration of the target gas remains above the alarm
values for 3 seconds or more, an alarm will be triggered.