Hach Portable Spectrophotometer DR 2800, Руководство пользователя

Страница: 90 / 126

90
Advanced Operations
6.5 Multi-Wavelength mode – measurements at more than one wavelength
In the multi-wavelength mode, absorbance values can be
measured at up to four wavelengths and the results can be
mathematically processed to obtain sums, differences and
relationships.
Absorbance measures the amount of light absorbed by the sample,
in units of absorbance.
% 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. Concentration is calculated using a
single factor for each wavelength, which is input by the user.
6.5.1 Set the reading mode at different wavelengths
Press Multi Wavelength in the Main Menu. Press Options for
Parameter Setup.
Table 13 Multi-wavelength setup options
Options Description
More For further Options
Store Off/On
With the Store On setting, all measurement data are stored automatically. With the Store Off
setting, no measurement data are stored.
% Trans/Abs To switch to % transmittance, concentration or absorbance readings
λ
Wavelength
To enter the measurement wavelength. Use the alphanumeric keypad to enter the measurement
wavelength. The entered wavelength must be in the range from 340–900 nm.
Timer icon
This functions as a stopwatch. It helps to ensure 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, an acoustic signal is emitted. The use of the timer has no influence on the measurement
program.
Concentration Factor Multiplication factor for converting absorbance values into concentration values.
Concentration
Resolution
To select the position of the decimal point in the calculated concentration readings.
Absorbance Formula Calculation basis for evaluating samples
Save as User Program To store the selected parameters as a User Program, see section 6.1 on page 61