Emerson Rosemount CT4400, Справочное руководство

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6 Gas calibration
6.1 Required tools
The gas concentrations measured by the analyzer can be validated against a known
sample gas or calibrated to match it by using the following gas calibration procedure.
To calibrate the analyzer, you need the following items:
• Nitrogen gas of instrument gas purity for use as a zero calibration gas
• Suitable span calibration gases for each gas measured
• Gas bottle pressure regulators
• Interconnecting hoses to connect the gas bottles to the analyzer
• A T-piece and excess flow line
NOTICE
In the case of gases, such as H
2
O, for which it is not normally possible to obtain calibrated
gas cylinders, it will usually be measured by the same laser as some other gas. Validating
the other gases measured by the analyzer (particularly any which are measured by the
same laser as H
2
O) can demonstrate that the system is functioning correctly, meaning
there is no need to calibrate the water measurement directly.
If calibration must be carried out (e.g., for legal requirements), it can be calibrated by
using a water vapor generator to supply a known concentration of water vapor.
6.2 Gas service menu definitions
The GAS SERVICE menu screen can be accessed from the Main Menu screen.
This gives the operator access to a number of software routines and screens that are used
for calibration and maintenance of the analyzer.
Where more options are available than can be displayed on the screen use the or
keys to scroll up or down onto the next page. The screen will continually wrap around until
the option required is highlighted.
Pressing the
Forward key
will move to the next screen where available as shown in the
GAS Service/Per Gas example below.
Pressing the screen Refresh key at any time will refresh the current display screen if
required by the operator.
PER GAS allows for gas calibration or verification on a gas by gas basis.
CALIBR ALL not an option available for the Rosemount CT4400 analyzer.
VERIFY ALL not an option available for the Rosemount CT4400 analyzer.
Reference Manual Gas calibration
00809-0100-4244 January 2020
Reference Manual 49