Hach DR 2800, User Manual, Page: 42 / 96

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Standard Operations
5.5.5 Sample Blank
Turbidity and color in the sample matrix can falsify the results of a
photometric analysis. The interference factors come from the
sample or are created by reactions with the reagents.
The influence of turbidity and/or color can be eliminated or reduced
by taking a sample blank reading.
In the barcode mode, a special cell (LCW919) containing the
sample blank is placed in the round cell compartment after the
sample reading has been taken, and is automatically measured.
The sample reading is then corrected by adding or subtracting the
blank value and the final result is displayed, together with the
message "After blank value corr.".
Some barcode tests do not require a sample blank value to be
determined, as turbidity and color are dealt with during the
test procedure.
5.5.6 Updating a Barcode Test
5.5.6.1 Manually Updating a Barcode Test
Using the data provided in the barcode, the instrument
automatically sets the measurement wavelength and factors. If a
discrepancy is detected between the barcode data and the stored
data, or a new test is identified, the instrument requests an update.
Data types are described in Table 5 . Instructions for editing values
are in the sections following Table 5.
Table 5 Program Update Options
Program point Description
Name Name of the analysis parameter
Version An abbreviation assigned by the user, or the version number, etc. is entered here
Measurement
process
Exact definition of the test: the number of wavelengths at which measurements are carried out, the
number of absorbance measurements needed, the keys to be used, any waiting periods between
measurements, etc.
Formula Definition of the formulas with which the test result is calculated
Variables
The number of variables shown in the display depends on the definition of the measurement
process and the formulas. Input of the numerical values of the wavelengths, factors, constants, etc.
Timer 1, Timer 2,
Timer 3, Timer 4
This function can be used to enter abbreviations and defined times for up to four timers. Activate
the appropriate line and press
EDIT
.
The timers are activated or deactivated with the control boxes on the left of the display. In the next
column, a selection can be made from a list of names that describe the corresponding work step. In
the third column, the times for each active timer are entered.