YOKOGAWA WE440, User Manual

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<3. Startup and Operation>
3-3
IM 12Y18A04-01EN 1st Edition : Oct. 04, 2019-00
3.6 Instrument Operation Modes
1 SAMPLE ANALYSIS
2 CALIBRATION
The instrument also operates cleaning and post wash cycles, along with a priming function useful
for startup and priming feed tubing lines to the reaction-measuring cell.
3.7 Sample Analysis and Validation
The SAMPLE ANALYSIS mode is similar to the calibration mode, with the exception that
during calibration the instrument calculates the relevant parameters correlating to the standard
concentrations used for calibration.
During sample analysis, the system relies on the CURRENT calibration parameters to calculate
the sample concentration.
Each measurement cycle starts with flushing the reaction cell with fresh sample. An auto blank
step makes sure that the background color of the sample is measured as a baseline. Typically,
reagents are added to develop the color of the final compound, and the intensity of the color
developed is measured and correlated to the sample concentration.
The validation cycle is similar to the measurement cycle except that the result is not reported
on the analog loops and not stored in the sample analysis results data storage. The result of
the validation analysis is displayed and printed on the RS-232 port. The validation cycle can be
executed on any available solution standard or sample selected by the user in the validation
setup parameters menu.
3.8 Calibration
The user may execute manual or set automatic calibration cycles at user defined intervals. In
the auto mode the analyzer calibrates periodically and checks the validity of the calibration per
the specified tolerance for the REFERENCE slope and offset parameters. New calibration data
is only accepted if it is within the limits of the specified tolerance for the REFERENCE calibration
parameters. The current column shows the current operating parameters that are used to
calculate the sample concentration.
3.9 Cleaning
Automatic flushing of the reaction cell may be programmed.
The default setup for the analyzer uses the sample as the cleaning solution. A cleaning cycle can
be performed by pressing:
STOP → MENU → MEASUREMENT → CLEAN
This cycle helps maintain clean reaction cell.
NOTE
To avoid damage and contamination to the reaction cell, use only cleaning solutions
recommended by the factory.