Measurement Computing WaveBook rev.3.0 - Manual (Page 134)

7-4 Calibration, 6-21-99 WaveBook User’s Manual
• Calibrate Channel: This button initiates 2-point calibration for the current calibration settings
displayed in the Calibration Parameters area. This calibration may be performed as often as desired for
the current Calibration Parameters. When the Calibrate button is clicked, the 2-Point Calibration
dialog box will be displayed.
The calibration will be performed on the Calibration Parameters (Chassis, Channel, Gain and
Bipolar) shown in the System Calibration dialog box. The user will be prompted to apply a voltage
source to the appropriate channel at the level indicated. The user may change the voltage level slightly
to suit the calibrator. After the voltage level has been applied, click the Calibrate button to begin the
calibration of the first point. The user will then be prompted to apply a new voltage level to the channel
for calibration of the second point. Again, the voltage level may be changed slightly to suit the
calibrator. The calibration of the second point is then initiated by clicking the Calibrate button. The 2-
point calibration for the current Calibration Parameters is now complete.
• Save: This button saves the calibration constants for the current Calibration Parameters indicated.
Before executing this command, the 2-point calibration for these settings must have first been
performed. The Save function will also automatically update the Calibration Parameters to reflect the
next Chassis, Channel, Gain and Bipolar parameters scheduled to be calibrated. Once this command
has been executed, however, you may not return to the previous Calibration Parameter settings. So, be
sure that you are satisfied with the calibration before executing the Save command.
• Skip: This button may be used to skip the current Calibration Parameters indicated and move to the
next scheduled Chassis, Channel, Gain and Bipolar setting. This button may be used if it is not
desirable to change the current Calibration Parameters indicated.
• Done: This button is used to exit the System Calibration dialog box. This may be used following the
successful calibration of the entire system or to exit the current calibration process.
• Custom: This button is used to customize the calibration procedure. Only a selected channel and
selected gains are calibrated.
WaveCal – Customization of Procedure
Manual Calibration
For calibration, the WaveBook supplies internal 0.000 V and 5.000 V (and 0.5000 V with WBK11). You
can calibrate all of the offsets and some of the gains using internal voltage references or external user-
supplied references. The host PC sets up the calibration, analyzes the measurements, determines the
correction factors, downloads them to the WaveBook for use during acquisition, and optionally saves them
in the WaveBook EEPROMs. Calibration occurs only when commanded by host PC software. For best
calibration, the software is able to adjust the calibration constants so that a user-supplied reference within a
limited calibration range is measured accurately.