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Chapter 5
Using the SCXI-1502
©
National Instruments Corporation
5-13
SCXI-1502 User Manual
Calibration
The SCXI-1502 is shipped with a calibration certificate and is calibrated at
the factory to the specifications described in Appendix A,
Specifications
.
Calibration constants are stored inside the calibration EEPROM and
provide software correction values your application development software
uses to correct the measurements for both offset and gain errors in the
module.
Internal/Self-Calibration
You can self-calibrate the SCXI-1502 in MAX by right-clicking the
module and selecting Self Calibrate. The NI-DAQmx Self Calibrate Device
function does the same. A self-calibration of the SCXI-1502 grounds all the
input channels and stores the resulting measurement as an offset correction
constant on the module. You should perform a self-calibration every time
you install the SCXI-1502 to a new system.
Note
You should self-calibrate the connected DAQ device before self-calibrating the
SCXI-1502.
External Calibration
If you have an accurate calibrator and DMM, you can externally calibrate
the SCXI-1502 gain and offset constants using NI-DAQmx functions.
The functions that are required for externally calibrating the SCXI-1502 are
available in NI-DAQmx 8.1 or later. Refer to the
NI-DAQmx Help
for
details about these functions.
Most external calibration documents for SCXI modules are available to
download from
ni.com/calibration
by clicking
Manual Calibration
Procedures
. For external calibration of modules not listed there, Basic
Calibration Service or Detailed Calibration Service is recommended. You
can get information about both of these calibration services from
ni.com/calibration
. NI recommends performing an external
calibration once a year.