Section 6
Calibration
of the Instrument for Measurement Analysis
40
Thermo Scientific Orion
2230XP Silica Analyzer
The calibration data is available for editing. From the MAIN MENU, follow the sequence:
MENU
➔
SETUP
➔
CALIBRATION PARAMETERS
The menu screen shows two columns labeled REFERENCE and CURRENT. The data in the
current column is the active data being used for slope and intercept, and the data in the
reference column is the data that the system relies on when comparing the new calibration
result to check its allowed deviation per the specified limit specified for the tolerance value.
High Range Dilution-Factor Calibration
The analyzer uses a dilution method for measurement of high concentrations. The cycle is
automatic and has been programmed at the factory. In most cases the factory default values
are sufficient for the specified range of the product. For improved accuracy, the user may
calibrate the dilution factor using a high concentration standard like a 3000 ppb. This calibration
is only allowed in manual mode, with user prompts and confirmation required at the end of the
cycle. Extended range calibration:
MENU
➔
SETUP
➔
(+) CALIBRATION PARAMETERS
Set the STANDARD CONC = 3000 ppb (for a 0 to 5000 ppb range). And execute a manual
calibration:
MAIN MENU
➔
MEASUREMENT
➔
CALIBRATE
➔
CALIBRATE
STANDARD
When the system detects a high absorbance level of the reacted solution, above the set limit, it
initiates the dilution cycle using the standard.
At the end of the cycle the dilution factor is calculated based on the value of the standard used
and the existing slope and intercept.
At the end of the calibration cycle the user is presented with the new calculated dilution factor to
accept or reject. The default dilution factor is 9.0 (range 8 to 10). The range depends on the
pump flow rate (pump #1) used to add the standard used for dilution dosing.
The user may edit the dilution factor in the ANALYSIS PARAMETERS menu:
MENU
➔
SETUP
➔
ANALYSIS PARAMETERS
➔
(+) (+) PAGE 3 OF 4
➔
DILUTION PARAMETERS
Consult the factory before modifying the default dilution steps. Press (+) to access the dilution
steps.
The automatic dilution cycle may be turned off using either a higher than expected AU limit:
