Vernier Original LabQuest - Manual (Page 14)

LabQuest Reference
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calibration for that sensor is read from the sensor when LabQuest identifies it. However,
some sensors require calibration.
Calibration requires that you have two reference
conditions available for a sensor. For example, for a pH
sensor you might have buffers of pH 4 and 10. We will
use that as an example here. Choose calibrate, selecting
the particular sensor as necessary. You will see the
calibration dialog. Tap the Calibrate Now button to
begin. Place the pH sensor in the pH 4 solution. Let the
reading stabilize a few seconds, or until you see only
small variations. Use the keyboard to enter a 4 in the
Reading 1 known value field, and tap Keep. Place the pH sensor in the pH 10 solution.
Enter 10 in the Reading 2 field. After the reading settles, tap Keep. Tap OK to complete the
calibration.
The one-point calibration option allows you to calibrate with only one reference. This only
introduces an offset in the reading, but this is sometimes all that is needed.
Calibration of the Stainless Steel Temperature Probe and Surface Temperature Probe are not
supported in LabQuest at this time.
The Units selection in the Calibration dialog allows you to alter the units of your calibration.
There are additional tabs on the Calibration dialog. Equation lets you view or alter the
numerical calibration information. Tap Apply if you make changes to use the new values.
Storage lets you choose how the new calibration will be saved. For example, if you perform a
calibration and want to go back to it later, have the storage option checked to save the
calibration with the LabQuest file. Tap OK; save the LabQuest file. Later, open that file, and
the calibration will be used. The Sensor Info tab contains information from the auto-ID chip
on the sensor, if present.
Tip: Use Logger Pro to write custom calibrations back to the sensor so that the calibration
will be used automatically whenever the sensor is used with LabQuest.
Zero
Zero will set the current sensor reading to zero by adding an offset to the current reading.
Not all sensors allow zeroing.
Reverse
Some sensors read both positive and negative. For example, the Force sensor reads positive
when it is pulled, and negative when compressed. Choosing the Reverse option will swap the
sign of the readings. Not all sensors can be reversed.
Graph Screen
LabQuest App automatically switches to the Graph screen when data collection begins.