how to self calibrate ni5112

[sido]

Once the ni5112 instrument has been returned from calibration:

Is it recommnded to perform self-calibration of the ni5112 using function niScope_CalSelfCalibrate(handle, "", 0); ?

Is it true that In doing this the instrument performs an internal calibration to calibrate gain and offset, trigger levels etc and stores the 'new' 'updated' calibration parameters in EEPROM and this is recommended by NI?

Is it recommended to perform this self-calibration periodically or just after installation post calibration? 

This self-cal enhances the accuracy of the instrument and does not invalidate calibration?

The function panel gives the CalSelfCalibrate third parameter two user selectable options 0 and 2,

0 = SelfCalibrate all channels, 2= Restore External Calibration

I was able to perform self-calibration, however, i got an error when i tried to restore external defaults. The error detailing that the ni5112 does not support this function. The function panel suggests you can restore cal data, the documentation says you can self calibrate but does not specifically detail restoring cal data.

What would have been the effect of restoring external calibration ?

Would the last cal data been reinstalled? or factory default settings?

[Sean_C.]

Hello Sido,

Thank you for contacting National Instruments.

Using self-calibration (or internal calibration), you can adjust the digitizer for use in environments other than those in which it was externally calibrated. Self-calibration does not rely on external standards—instead, it adjusts the digitizer with respect to an onboard, high-precision voltage source. Use self-calibration whenever you use the digitizer in an environment where external variables such as temperature can affect measurements.

It is recommended that you self calibrate every 90 days or when the temperature is more than 5 degrees different than the temperature at which the device was last calibrated.

Because the internal reference on the digitizer is first externally calibrated to a NIST-traceable source, self-calibration preserves the traceability of the calibration.

The error you received is correct.  The 5112 does not support the "Restore External Calibration" option.

I hope this helps.  Please let me know if you have any further questions.

Regards,
Sean Close

[Sean_C.]

"What would have been the effect of restoring external calibration ?

Would the last cal data been reinstalled? or factory default settings?"

The NI 5911 is the only device which supports this option.  When this option is selected, the factory default settings are restored.

Regards,
Sean Close