©NationalInstruments Corporation 3 SCXI-1125Calibration Procedure

Documentation

The NI-DAQ Function Reference Online Help file and NI-DAQ User
Manual for PC Compatibles containdetailedinformationonusingthe
NI-DAQ driver. The function reference online help file includes detailed
information ont he driver functions. You can access the online help by
clicking Start»Programs»NationalInstruments DAQ»NI-DAQ Help.
Theuser manual provides instructions on installing and configuring
National Instruments DAQ devices. This manual also includes detailed
informationon creating applications that use the NI-DAQ driver. These are
your primary references for writing your calibration utility. For further
information on the products you are calibrating, refer to your device user
manuals.

TestConditions

Follow these guidelines to optimize the connections and the environment
during calibration:
•Keepconnections to the SCXI module short. Long cables and wires act
asantennae, picking up extra noise and thermal offsets that can affect
measurements.
•Use shieldedcopper wire for all cable connections to the device.
Use twisted-pairwire to eliminate noise and thermal offsets.
•Maintain the temperature between 18 and 28 °C.
•Keeprelative humidity below 80%.
•Allowa warm-up time of at least 15 minutes for the SCXI module and
30minutes for the E Series device to ensure the measurement circuitry
is at a stable operating temperature.
Calibration
The calibration process consists of the following steps:
1. Setting up the devicefo rtestin g.
2. Verifyingthe existing operation of the device to determine whether it
is operating within its specifications.
3. Adjustingthe device with respect to a known voltage source.
4. Verifyingthat the device is operating within its specifications after
adjustments.