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National Instruments Corporation
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6703/6704 Calibration Procedure
minimizing the errors on the calibration channels also minimizes the errors
for all of the voltage and current outputs.
External Calibration
External calibration uses a high-precision voltage and current device to
measure errors on the board outputs. These errors are then corrected with a
set of calibration constants that adjust the offset and gain of the 16-bit
DAC. This ensures that the output voltages and currents fall within the
board specifications.
Because of the 6703/6704 calibration circuitry, the only calibration
adjustment you must make is to adjust the values of the calibration channels
to account for time- or temperature-related drift of the onboard reference.
The board is calibrated at the factory and the calibration constants are
loaded into nonvolatile memory.
How Long Does Calibration Take?
Automated calibration procedures can reduce the calibration and
verification process to approximately 10 minutes. However, manual
calibration and verification can take as long as 1 hour. You can automate
the adjustment and verification procedure if you have access to
programmable standards such as the Fluke 5700A or HP3458A, which can
be controlled via a GPIB connection. You can then program the entire
procedure to save time and effort.
Equipment and Other Test Requirements
This section describes the test equipment, software, calibration functions,
and environment needed to calibrate your 6703/6704 board. Before
calibrating your board, you must perform the following steps:
1.
Install the NI-DAQ driver on the calibration computer. For specifics on
NI-DAQ, refer to the
section later in this document.
2.
Properly configure the board to be calibrated. For configuring
instructions, refer to the
Configuring Your Board in NI-DAQ
later in this document.
3.
Write calibration software to communicate with the board via NI-DAQ
function calls. For information on writing software, refer to the
section later in this document.
