PASCO Xplorer GLX, Руководство пользователя

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X p l o r e r G L X U s e r s ’ G u i d e 73
One-Point Offset
In a one-point offset calibration, you reset only one point.
The line shifts so that it intersects the new point, but its slope does not change.
One-point slope calibration; the line shifts to intersect the new point
Offset calibration is usually used to make one sensor agree with another sensor.
The graph below on the left shows the measurements from two temperature
probes in the same container of water. Due to normal variation among probes, the
second probe consistently reads about 0.08 °C higher than the first probe. Nor-
mally this difference would be insignificant; however, an offset calibration can
be used to bring the sensors into closer alignment. See “One-Point Offset Cali-
bration or Multiple-Measurement Alignment Procedure” on page 77 for step-by-
step instructions.
Navigating in the Calibration Dialog Box
For step-by-step instructions on the calibration procedure, see page 75.
The Calibration dialog box contains a list of fields that are used to select the mea-
surement (or measurements) to be calibrated, and to enter the parameters of the
calibration. One of the fields is always highlighted. Use the up and down arrow
keys to move the highlight to a different field.
You will sometimes see an up or down arrow ( or ) near the bottom of the
dialog box indicating that more fields are available, but not currently visible.
When you see the up arrow displayed on the screen, you can press the up arrow
key on the keypad multiple times to make more fields visible. When you see the
down arrow displayed on the screen, you can press the down arrow key to make
more fields visible.
new
point old
calibration
new
calibration
Input Dat
a
Output Data
line shifts
Before offset calibration After offset calibration
One measurement
is shifted to align
with other
measurement