Fluke NetDAQ 2640A, Service Manual

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NetDAQ
Service Manual
4-38
4. Resolve any calibration problems based on the following:
•
An execution error !> is returned by the CAL_STEP? command if the full scale
measurement is off by more than 5% from the target or if the zero measurement
is off by more than 1% of full scale from the target. When an error is detected,
the cal constant is not updated, and the procedure remains at the same step.
•
When CAL_STEP? reports an execution error !> due to an out-of-range
measurement, it returns the raw measured reading to give you an indication of
what was measured. When CAL_STEP? completes successfully, it returns the
reference value.
•
If CAL_STEP? returns an execution error !> while measuring the short circuit
on channel 2, the procedure freezes at the internal step that measures the short.
This way, you can send a CAL_REF? command and it will return 0 V, indicating
that the problem was probably caused by a misapplied short on channel 2.
•
A device-dependent error is returned by the CAL_STEP? command if an internal
error such as a measurement timeout is detected. When an error is detected, the
cal constant is not updated, and the procedure remains at the same step.
•
An execution error !> is returned by the CAL_REF command if the specified
reference is less than 33% of full scale or greater than 100% of full scale.
Manual VAC Calibration Procedure 4-44.
The VAC calibration procedure calculates gain and offset calibration constants for all of
the VAC ranges.
Complete the following procedure to manually calibrate the VAC function.
1. If you have not already done so, complete the procedure “Preparing for Calibration”
earlier in this chapter.
2. Connect the instrument and 5700A Calibrator as shown in Figure 4-7.
3. Complete the sequence of manual steps shown in Table 4-6. Measurements are made
on channel 1 for each VAC range: one at 10% of full scale and one at 100% of full
scale. All AC voltages must be applied at 1 kHz. The VAC gain and offset
calibration constants for each range are determined from the two measurements.
4. Resolve any calibration problems based on the following:
•
An execution error !> is returned by the CAL_STEP? command if the full-scale
measurement is off by more than 10% from the target or if the low-scale
measurement is off by more than 1% of full scale (10% from the target). When
an error is detected, the cal constant is not updated, and the procedure remains at
the same step.
•
A device-dependent error is returned by the CAL_STEP? command if an internal
error such as a measurement timeout is detected. When an error is detected, the
cal constant is not updated, and the procedure remains at the same step.
•
An execution error !> is returned by the CAL_REF command for the full scale
measurement if the specified reference is less than 33% of full scale or greater
than 100% of full scale for any range. An execution error !> is returned by the
CAL_REF command for the low scale measurement if the specified reference is
less than 10% of full scale or greater than 30% of full scale for any range.