National Instruments PXIe-4340, Процедура калибровки

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NI PXIe-4340 Calibration Procedure | © National Instruments | 9
g. Compare the AC Amplitude measurement to the Excitation Accuracy Limits in
Table 7. If the measurement is between these values, the device passes the
AC Amplitude test at this Excitation Voltage.
5. Repeat step 4 for the other Voltage Excitation Values in Table 7.
6. Repeat steps 1 to 5 for each additional channel to be verified.
7. Disconnect the PXI-4070 from the TB-4340.
Ratiometric Accuracy
Complete the following steps to connect the TB-4340 for ratiometric accuracy verification:
1.
Install the PXIe-4340 and the TB-4340 in the PXI Express chassis according to the
instructions in the
NI PXIe-4340 and TB-4340 User Guide and Terminal Block
Specifications
.
2. Connect AI+ and AI- according to the measurements in Table 8 for each measurement.
Complete the following steps for each measurement test point to verify the ratiometric accuracy
of the PXIe-4340:
1.
Connect the channel as shown in Table 8. Leave all other pins disconnected.
2. Configure the channel as shown in Table 5 for 7 Vrms excitation.
3. Perform the configured AI LVDT measurement and average the acquired measurements.
4. Compare the resulting average to the
Minimum Limit
and
Maximum Limit
values shown in
Table 8. If the result is between these values, the device passes the test.
Table 7.
Excitation Accuracy Limits
Measurement Nominal Maximum Limit Minimum Limit
Excitation Amplitude 7 Vrms Point 7 Vrms 7.35 Vrms 6.65 Vrms
Excitation Amplitude 5 Vrms Point 5 Vrms 5.25 Vrms 4.75 Vrms
Excitation Amplitude 3 Vrms Point 3 Vrms 3.15 Vrms 2.85 Vrms
Excitation Amplitude 1 Vrms Point 1 Vrms 1.05 Vrms 0.95 Vrms
Table 8. Verification Connections
Measurement Short AI+ to Short AI- to
Nominal
Reading Maximum
Limit
Minimum
Limit
1 V/V EX+ EX- 1 V/V 1.0004000 V/V 0.999600 V/V
0 V/V AI- AI+ 0 V/V 0.000150 V/V -0.000150 V/V
-1 V/V EX- EX+ -1 V/V -0.999600 V/V -1.000400 V/V
Note : NI-DAQmx returns units scaled for length, while the PXIe-4340 accuracy is specified as a voltage
ratio. With sensitivity set to 1 mV/V/mm and output units set to meters as in Table 5, 1 meter is numerically
equivalent to 1 V/V.