Hach-Lange DR 3900 User Manual - Manual (Page 97)

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Expanded programs
6.4 Single Wavelength (absorbance, concentration and transmittance
readings)
The Single Wavelength mode can be used in three ways. For
sample readings at a single wavelength, the instrument can be
programmed to measure the absorbance, % transmittance or
concentration of the analyte.
• Absorbance readings: The light absorbed by the sample is
measured in absorbance units.
• % Transmittance measures the percent of the original light
that passes through the sample and reaches the detector.
• Turning on the concentration factor allows selection of a
specific multiplier for converting absorbance readings to
concentration. In a graph of concentration versus the
absorbance, the concentration factor is the slope of the line.
6.4.1 Set up Single Wavelength mode
1. Press Single Wavelength in the Main Menu.
2. Press Options for Parameter Setup.
Table 12 Options for Single Wavelength
Options Description
More For further Options
Recall measurement
data symbol Recall saved measurement data, wavelength scans or time courses, refer to section 5.3,
page 43 .
%Trans/Ext (%
Trans/Abs)
To switch to % transmittance, concentration or absorbance readings
λ Wavelength
To input the wavelength setting. Use the alphanumeric keypad to enter the reading wavelengths.
The entered wavelength must be in the range from 320-110 nm.
Timer icon
This functions as a stopwatch. It helps to make sure that the steps of an analysis are correctly
timed (e. g. reaction times, wait times, etc., can be exactly specified). When the specified time
has elapsed, a sound is emitted. The use of the timer has no influence on the reading program.
Concentration Factor Multiplication factor for converting absorbance values into concentration values.
Concentration
Resolution
To select the number of decimal places.