Instruction manual

7.0 STARTUP SM425 INSTRUCTION MANUAL
7.12.1.2
7.12.1.3
Select the Calibration Points
Select “Points” in the Calibration setup display screen. Select “Both” if performing the initial calibration for
commissioning the analyzer.
Set the Calibration Gas Concentrations
1. Zero-gas concentration: Select “zero gas conc” and enter the value of zero calibration gas
concentration using the Numeric-data Entry screen; if the oxygen concentration is 0.98 vol% O2,
enter 00098.
2. Span-gas concentration: Select “span gas conc” and enter the value of span calibration gas
concentration using the Numeric-data Entry screen; if instrument air is used, enter 02100 for a 21
vol% O2 value. If using the ZO21S Standard Gas Unit and atmospheric air as the span gas,
determine the actual oxygen concentration with a hand-held oxygen analyzer and enter it.
If instrument air is used for the span gas, dehumidify the air to a dew point of -20°C and filter any oil or
particulate.
7.12.2 Manual Calibration Procedure
7.12.2.1
7.12.2.2
Preliminary Checks
Before performing a manual calibration, verify the ZA8F Flow Setting Unit zero-gas flow valve is fully
closed. Set the zero-gas cylinder pressure regulator to a secondary pressure equaling process gas
pressure plus approx. 50 kPa (or process gas pressure plus approx. 150 kPa if a check valve is used).
Maximum pressure rating is 300 kPa.
This applies even if the SM425CAL Autocalibration Unit is used.
Calibration Procedure
This procedure assumes instrument air is used as the reference for the span gas. Follow the steps below
to conduct manual calibration:
1. Select the Setup key in the basic panel display screen to display the Execution/Setup display
screen. Then select Calibration. The Calibration execution display screen shown in Figure 7-23
appears.
Figure 7-23 Calibration Display
42500001 REV A 115