Measurement / Calibration / Switching Off - Emerson ROSEMOUNT Analytical NGA 2000 Instruction Manual

Instruction Manual
90002929
07/2005
7.

Measurement / Calibration / Switching Off

7.1 Measurement
The primary step in the measurement of the concentration of a gas component is the admission
of sample gas to the analyzer.
Note!
Take care for the start-up procedure before measurement (chapter 6.)!
Admit sample gas at the respective gas inlet fitting (see Item 5.).
Note!
For MLT 3 for gas purity measurement the sample gas need to be
conditionned to the ambient temperature of the analyzer!
Set the gas flow rate to allowable rate.
Before starting an analysis, however, the following should be performed:
entry of the desired MLT parameters,
calibration of the MLT (see Item 7.2).
Note for analyzers with electrochemical EO
Depending on measuring principle the electrochemical EO
of oxygen (residual humidity avoids drying of the cell). Admit cells continuously with sample gas of low
grade oxygen concentration or with oxygenfree sample gas could result a reversible detuning of O
sensitivity. The output signal will become instabil.
For correct measurement the cells have to admit with a O
We recommend to use the cells in intervall measurement [purge cells with conditioned (dust removal but
no drying) ambient air at measurement breaks].
If it is necessary to interrupt oxygen supply for several hours or days, the cell have to regenerate (supply
cell for about one day with ambient air). Temporary flushing with nitrogen (N
zeroing) will have no influence to measuring value.
Note for analyzers with electrochemical TEO
For TEO sensor please note that the gas inlet and outlet connections of the analyzer are sealed to prevent
2
exposure of the sensor to air.
Prolonged exposure of the sensor to air can cause extended start up time, reduction of performance or
damage to the sensor. Do not remove the sealing caps until all associated sample handling components
are installed and the instrument is fully ready for installation.
Emerson Process Management GmbH & Co. OHG
MEASUREMENT/CALIBRATION//SWITCHING OFF
cell!
2
cell needs a minimum internal consumption
2
concentration of at least 0.1 Vol.-%.
2
cell!
2
NGA 2000 MLT Hardware
MEASUREMENT
) for less than 1 h (e.g. analyzer
2
2
7 - 1