National Instruments NI PXI-5922, Manual

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10 | ni.com | NI 5922 Calibration Procedure
External Calibration Procedures
The complete external calibration procedure consists of self-calibrating, verifying the
performance of the oscilloscope, adjusting the calibration constants, and verifying again after the
adjustments. In some cases, the complete calibration procedure may not be required. Refer to the
External Calibration Options section for more information.
The external calibration procedure automatically stores the calibration date to allow traceability.
Verifying NI 5922 Specifications
Note
After the 15-minute warm-up time, always self-calibrate the NI 5922 before
beginning a verification procedure.
This section describes the program you must write to verify either the calibration test limits or
the published specifications for the NI 5922. Refer to the
External Calibration Options section
to determine which limits to use in these procedures.
All verification procedures described in this section begin with
niScope_init
(niScope
Initialize VI) with resetDevice set to
NISCOPE_VAL_TRUE
and end with
niScope_close
(niScope Close VI).
If any of these tests fail immediately after you perform an external adjustment, verify that you
have met the required test conditions listed in the
External Calibration Requirements section
before you return the oscilloscope to NI for repair.
Vertical Offset Accuracy
Complete the following steps to verify vertical offset accuracy of the NI 5922. You must verify
both channels and each iteration listed in Table 3.
1.
Disconnect all cabling from the BNC inputs of the NI 5922. No input signal is needed
because the NI 5922 internal 50
Ω resistor connects the input to ground.
2. Call
niScope_ConfigureChanCharacteristics
(niScope Configure Chan
Characteristics VI) with the following parameters:
•
channelList :
"0"
• inputImpedance :
NISCOPE_VAL_50_OHM
• maxInputFrequency :
0
3. Call
niScope_ConfigureVertical
(niScope Configure Vertical VI) with the
following parameters:
•
channelList :
"0"
• range : The Range value for the current iteration from Table 3
• offset :
0.0
• coupling :
NISCOPE_VAL_DC
• probeAttenuation :
1.0
• enabled :
NISCOPE_VAL_TRUE