©
National Instruments Corporation
3
NI 446X Calibration Procedure
Calibration Options
NI 446
X
devices support two types of calibration: self-calibration and
external calibration.
Self-Calibration
Self-calibration, also known as internal calibration, uses a software
command and requires no external connections. Self-calibration improves
measurement accuracy by compensating for variables such as temperature
that might have changed since the last external calibration. Self-calibration
retains the traceability of the external calibration.
External Calibration
External calibration is generally performed with high-precision
instruments at either NI or a metrology lab. This procedure replaces all
calibration constants in the EEPROM and is equivalent to a factory
calibration at NI. Because the external calibration procedure changes all
EEPROM constants, it invalidates the original calibration certificate. If an
external calibration is done with traceable instruments, a new calibration
certificate can be issued.
Software and Documentation Requirements
This section describes the software and documentation required for both
self-calibration and external calibration.
Software
Install NI-DAQmx 8.1 or later on the calibration computer. You must have
the proper device driver installed on the calibration system before
calibrating the device.
Note
NI recommends that you install the NI-DAQmx driver software before physically
installing the NI 446
X
device. NI-DAQmx, available at
ni.com/downloads
, configures
and controls the NI 446
X
.
NI-DAQmx supports a number of programming languages, including
LabVIEW, LabWindows
™
/CVI
™
, Microsoft Visual C++ 6.0, Microsoft
Visual Basic 6.0, Microsoft .NET, and Borland C++.
If you want to write the calibration procedure using LabVIEW, NI
recommends that you use the Full or Professional Development System or
the Developer Suite Professional Edition. These editions include