INST No INE -403-0P0
−
29
−
Absorbance (x)
M
o
is
tu
re
v
a
lu
e
(y
)
(% H
2
O
)
7.3 Preparation of calibration curves
Create a calibration curve by plotting data obtained by
[7.2 Sample measurement] on a graph. Plot the
absorbance "x" of this moisture meter on the X-axis
and also plot the moisture value (%H
2
O) on the Y-axis.
Obtain a curve with minimize errors from this graph as
a calibration curve. Usually the curve with minimize
errors is obtained by the regression operation. For the
creation of a calibration curve by the regression
operation, refer to [7.3.1 Computation of regression
expression] and [7.3.2 Confirmation of regression
expression].
If a graph contains inflection points, use the creation of
a calibration curve by broken line approximation. For
the creation of a calibration curve by broken line
approximation, refer to [6.4 Creation of calibration
curve by broken line approximation].
7.3.1 Computation of regression expression
This moisture meter has regression operation function by the minimum mean square method.
By this function, first-degree to third-degree polynomials can be obtained by entering the data
obtained in [7.2 Sample measurement].
Assume that there are “n” sets of sample data ("x
n
, y
n
). (in condition that “n” is 20 or less)
(1) Setting of calibration curve number
1) Press SEL key and CH/. key simultaneously
for 2 seconds to enter into the sample data setting mode.
2) By pressing key, a numeric blinks for entering a
calibration curve number.
3) Change the numeric by key, key or key.
When key is pressed, the numeric is increased.
When key is pressed, the numeric is decreased.
When key is pressed, the blinking digit shifts.
4) When ENT key is pressed, the numeric stops blinking
and the calibration curve number is stored.
(2) Setting of data count
1) Press SEL key to enter into the data count setting
mode.
2) Change a numeric by the procedure mentioned in the
above “(1) Setting of calibration curve number 2) and
3)” and store it with ENT key.
CH
DATA
CH
0
CH
DATA
CH
00
CH
DATA
n
3
Setting data
displayed
Setting data number
displayed
Blinking
Calibration
Curve number
7. Preparation of calibration curves
