Stanford Research Systems SR850 User Manual page 146

Math Menu
re-entered, the View Parameters function will re-display the best fit curve
and the parameter window.
Both the Do Fit and View Parameters functions result in a display screen
like the one shown below.
Full Scale = 100 mV
Dyn Reserve = 23 dB 12 dB/oct Line
Trace 2 Y
y = a + b•(t-t0)
t0 = 9.600000e+001 s
a = -2.875882e-003
b = 1.136381e-003
center = 0.0
Press Any Key To Continue...
In this example screen, the fit is a line. The curve fit region is delimited by
the two limit markers (heavy dashed vertical lines) as described below.
The final curve fit is plotted between the limit markers along with the
data. The parameters of the fit are displayed in the window at the center.
Each type of fit has a different parameter display. The horizontal coordi-
nate is t (cursor readout in time, i.e. increasing to the right) and the verti-
cal coordinate is the trace value (in the units of the display).
Line Fit: y = a + b•(t - t
t = horizontal offset in time
0
a = vertical offset in trace units
b = slope in trace units/second
y = ae -(t - t
Exp. Fit:
t = horizontal offset in time
0
a = amplitude in trace units
b = time constant in time
c = vertical offset in trace units
y = ae -
Gauss. Fit:
t = peak center position in time
0
a = amplitude in trace units
b = line width in time
c = vertical offset in trace units
5-36
100 mS Syncro
2xLin AC A
7.000 S 36.100 e-3
10 S /div
50.00 e-3 V
)
0
)/b + c
0
( t/b) 2 + c where t = t - t
1/2
Do Fit:
Type of Fit
Line Exp
Gauss
View
Params:
Limits
Left:
Right:
0.000 S
Return:
0