•
Allow a warm-up time of at least 30 minutes after the chassis is powered on and
NI-DCPower is loaded and recognizes the PXIe-4137. The warm-up time ensures that the
PXIe-4137 and test instrumentation are at a stable operating temperature.
•
Use shielded copper wire for all cable connections to the device. Use twisted-pair wire to
eliminate noise and thermal offsets.
•
To ensure the system has had adequate time to settle, wait one second after requesting a
new current or voltage or after changing a load before taking a measurement.
•
Keep relative humidity between 10% and 70%, noncondensing.
•
When making measurements, configure the following aperture time-related settings:
–
Set the
niDCPower Aperture Time
property or
NIDCPOWER_ATTR_APERTURE_TIME
attribute to 2 power-line cycles (PLCs) on
the device.
–
Set the
niDCPower Aperture Time Units
property or
NIDCPOWER_ATTR_APERTURE_TIME_UNITS
to power line cycles.
–
Set the
niDCPower Configure Power Line Frequency
property or the
NIDCPOWER_ATTR_POWER_LINE_FREQUENCY
attribute to either 50 or 60
depending on the frequency of the AC power line in your location.
•
Do not use the NI-DCPower Soft Front Panel (SFP) to request test points for any
adjustment functions because you cannot set aperture time using the SFP.
•
Ensure that properties or attributes for the device that are not specified in calibration
procedures are set to their default values.
•
When making measurements, configure any specified digital multimeters (DMMs) with
the best available ranges and measurement settings for each specified test point.
•
For verification procedures, maintain an ambient temperature of 23 °C ± 5 °C. Maintain
an internal device temperature range of T
cal
±1 °C.
1
•
For adjustment procedures, maintain an ambient temperature of 23 °C ±1 °C. The
PXIe-4137 internal temperature is greater than the ambient temperature.
Safety Guidelines for System Operation
Caution
Hazardous voltages of up to the maximum voltage of the PXIe-4137 may
appear at the output terminals if the safety interlock terminal is closed. Open the
safety interlock terminal when the output connections are accessible. With the safety
interlock terminal open, the output voltage level/limit is limited to ±40 V DC, and
1
T
cal
is the internal device temperature recorded by the PXIe-4137 at the completion of the last self-
calibration. Call the niDCPower Get Self Cal Last Temp VI to query T
cal
from the PXIe-4137.
4
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NI PXIe-4137 Calibration Procedure
