PerkinElmer aanalyst 200 User Manual page 176

Touch Screens
Standard Concentrations
1 – 8
Reslope
Calibration Equation dialog in Calibration subpage
The calibration equation describes the mathematical relationship between the absorbance reading
and the concentration of the analyte in the solutions being measured. Various calibration
equations are available, depending on whether the calibration curve is linear or non-linear,
whether it passes through the origin or makes an intercept with the absorbance axis, and on the
technique of calibration used.
Nonlinear Through
Zero:
Linear Through
Zero:
Through Zero:
Method Addition
7-18
Touch-entry fields that display the selected concentrations of up
to 8 standards (calibration solutions).
To enter the concentration of a standard, touch the required field
to display the Standard Conc. dialog. Enter the required
concentration and then touch OK.
Reslope can only be used with equations linear through zero,
non-linear through zero, and linear through zero calculated
intercept. Touch-entry field that displays the selected
concentrations of the reslope solution. The reslope option allows
you to make small corrections to the calibration curve using a
single standard to compensate for minor changes in instrument
conditions. A reslope standard near the middle of the calibration
range usually gives the best results.
To enter the concentration of a reslope solution, touch this field
to display the Reslope dialog. Enter the required concentration
and then touch OK.
Reslope would appear in Analyze page as one of the standard
selections when the appropriated standard calibration equation is
selected. If the calibration equation, Through Zero had been
selected.
Select this option if you expect the concentration of the analyte in your
samples to be outside the linear range.
This option covers the widest concentration range and you need a larger
number of standards (calibration solutions) to establish the calibration
curve. A calibration curve defined using this equation is forced to pass
through zero absorbance and zero concentration (i.e. the origin).
Select this option if you expect the concentration of the analyte in your
samples to be within the linear range.
A calibration curve defined using this equation is forced to pass through
zero absorbance and zero concentration (i.e. the origin).
You select the analyte addition technique when the composition of the
sample is unknown and the matrix causes an interference that varies in
magnitude from sample to sample. With this technique, every unknown