MSA TG5000, Operating Manual

Page: 43 / 75

43
Operation
Span Value
The span value is used to set the calibration point. The default span values are approximately half
of the total range of the sensor as purchased (see Tab. 14). If the range is changed, the span value
should also be changed to increase accuracy over the full-scale range.
Before changing the span value, the user should ensure that the appropriate concentration of cali-
bration gas is available. The concentration of the calibration gas should match the span value,
except if using propane to calibrate a combustible sensor to a different gas cross reference value.
To change the span value:
(1) Scroll to Settings and select it.
(2) Select Sensor.
(3) Scroll and select Span Value.
(4) Current Span Value is displayed.
(5) Enter desired span value.
(6) Scroll and select Save.
Default and range of available span values depends on the sensor type. See Tab. 14
for default and range of span values.
Sensor Range
All XCell sensors have adjustable sensor ranges. The sensor range cannot be set below the
current alarm set points. The user may need to first lower alarm set points and/or span value in
order to adjust sensor range to desired level. The user should also consider adjusting the span
value to accommodate the changed sensor range so that the span is in the center of the range.
To change the sensor range:
(1) Scroll to Settings and select it.
(2) Select Sensor.
(3) Scroll and select Sensor Range.
(4) Current sensor range is displayed.
(5) Enter desired sensor range.
(6) Scroll and select Save.
Changing the sensor range will change the analog output values for alarm levels.
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