National Instruments PXIe-4480 Manual

CALIBRATION PROCEDURE
PXIe-4480/4481
6-Channel, 24-bit, 1.25 MS/s DSA Analog Input
This document contains the verification and adjustment procedures for the PXIe-4480 and
PXIe-4481 Dynamic Signal Acquisition (DSA) analog input modules. The procedures for the
PXIe-4481 are a subset of those for the PXIe-4480, specifically with regards to the absence of
the charge measurement function, which is available on the PXIe-4480, but not the PXIe-4481.
However, for clarity, the adjustment procedures for each module are listed separately. For more
information about calibration solutions, visit ni.com/calibration.
Contents
Software.................................................................................................................................... 1
Documentation.......................................................................................................................... 2
Test Equipment......................................................................................................................... 3
Connecting the PXIe-4480/4481 .............................................................................................. 6
Test Conditions......................................................................................................................... 12
Initial Setup............................................................................................................................... 12
Verification............................................................................................................................... 12
Adjustment (PXIe-4480) .......................................................................................................... 21
Adjustment (PXIe-4481) .......................................................................................................... 28
Reverification ........................................................................................................................... 33
Updating the Calibration Date without Performing Adjustment.............................................. 33
Specifications............................................................................................................................ 33
Where to Go for Support .......................................................................................................... 34
Software
Calibrating the PXIe-4480/4481 requires the installation of NI-DAQmx on the calibration
system. NI-DAQmx 16.1 added driver support for the PXIe-4480/4481. For the list of devices
supported by a specific release, refer to the NI-DAQmx Readme, available on the
version-specific download page or installation media.
You can download NI-DAQmx from ni.com/downloads. NI-DAQmx supports LabVIEW,
LabWindows™/CVI™, C/C++, C#, and Visual Basic .NET. When you install NI-DAQmx, you
only need to install support for the application software that you intend to use.

2|ni.com |NI PXIe-4480//4481 Calibration Procedure
Documentation
Consult the following documents for information about the PXIe-4480/4481, NI-DAQmx, and
your application software. All documents are available on ni.com and help files install with the
software.
PXIe-4480/4481 Getting Started Guide
NI-DAQmx driver software installation and hardware setup
PXIe-4480/4481 Specifications
PXIe-4480/4481 specifications and calibration interval
DAQ Getting Started Guide for PXI/PXI Express
Information about hardware and software installation, device configuration, and
programming
NI-DAQmx Readme
Operating system and application software support in NI-DAQmx
NI-DAQmx Help
Information about creating applications that use the NI-DAQmx driver
LabVIEW Help
LabVIEW programming concepts and reference information about NI-DAQmx
VIs and functions
NI-DAQmx C Reference Help
Reference information for NI-DAQmx C functions and NI-DAQmx C properties
NI-DAQmx .NET Help Support for Visual Studio
Reference information for NI-DAQmx .NET methods and NI-DAQmx .NET
properties, key concepts, and a C enum to .NET enum mapping table

NI PXIe-4480/4481 Calibration Procedure |© National Instruments |3
Test Equipment
Table 1 lists the equipment recommended for the performance verification and adjustment
procedures for the PXIe-4480. Table 2 lists the same for the PXIe-4481. If the recommended
equipment is not available, select a substitute using the minimum requirements listed in the
table.
Table 1. Recommended Equipment (PXIe-4480)
Equipment
Recommended
Model(s) Where Used
Minimum
Requirements
Calibrator Fluke 5700A AI Gain Frequency Range:
40 Hz to 200 kHz
Voltage Range:
up to 6.3 Vrms
ACV Accuracy:
40 Hz: 0.017%
1 kHz: 0.016%
20 kHz: 0.017%
50 kHz: 0.037%
100 kHz: 0.086%
200 kHz: 0.32%
Function Generator Keysight (Agilent)
33250A series
Timebase
Frequency
Frequency Range:
up to 90 kHz
Frequency Accuracy:
2ppm
Voltage Range:
up to 9 Vpk
Digital Multimeter PXI-4070 IEPE Current Current Accuracy:
0.9%
InfiniBand 12X-6BNC
Cable
National
Instruments
SHB12X-6BNC
All N/A
BNC Shorting Cap
(quantity 6)
Pomona
Electronics 5085
or
Pomona
Electronics
3840-50
AI Offset Resistance: ≤50 Ω

4|ni.com |NI PXIe-4480//4481 Calibration Procedure
BNC (F) to Banana Plug
Adapter
Pomona
Electronics 1269
AI Gain N/A
BNC (M) Cable*
(quantity 1 minimum,
11 maximum)
Pomona
Electronics 5697
AI Gain Characteristic
Impedance: 50 Ω
BNC F-F-F T-Connector*
(quantity 0 minimum,
5 maximum)
Pomona
Electronics 3284
AI Gain Characteristic
Impedance: 50 Ω
Calibration Capacitor†Meggitt Endevco
2947C
Charge Gain 1000 pF 1% C0G,
calibrated to 0.1%
10-32 (M) to BNC (M)
Interface Cable†
PCB Piezotronics
002C03
Charge Gain N/A
*AI Gain verification and adjustment can be conducted one channel at a time, all six channels
simultaneously, as well as any number in between. The minimum quantity corresponds to one channel
at a time. The maximum quantity corresponds to all six channels simultaneously.
†Charge verification/adjustment is optional.
Table 1. Recommended Equipment (PXIe-4480) (Continued)
Equipment
Recommended
Model(s) Where Used
Minimum
Requirements

NI PXIe-4480/4481 Calibration Procedure |© National Instruments |5
Table 2. Recommended Equipment (PXIe-4481)
Equipment
Recommended
Model(s) Where Used
Minimum
Requirements
Calibrator Fluke 5700A AI Gain Frequency Range:
40 Hz to 200 kHz
Voltage Range:
up to 6.3 Vrms
ACV Accuracy:
40 Hz: 0.017%
1 kHz: 0.016%
20 kHz: 0.017%
50 kHz: 0.037%
100 kHz: 0.086%
200 kHz: 0.32%
Function Generator Keysight (Agilent)
33250A series
Timebase
Frequency
Frequency Range:
up to 90 kHz
Frequency Accuracy:
2ppm
Voltage Range:
up to 9 Vpk
InfiniBand 12X-6BNC
Cable
National
Instruments
SHB12X-6BNC
All N/A
BNC Shorting Cap
(quantity 6)
Pomona
Electronics 5085
or
Pomona
Electronics
3840-50
AI Offset Resistance: ≤50 Ω
BNC (F) to Banana Plug
Adapter
Pomona
Electronics 1269
AI Gain N/A

6|ni.com |NI PXIe-4480//4481 Calibration Procedure
Connecting the PXIe-4480/4481
This section describes the options in connecting the PXIe-4480/4481 to the calibration
equipment.
Voltage Offset Accuracy Verification/Adjustment
Figure 1 illustrates the connections for voltage offset accuracy verification/adjustment.
Figure 1. Voltage Offset Accuracy Connections
Note Secure the cable to the module front panel using the cable connector
jackscrews.
BNC (M) Cable*
(quantity 1 minimum,
11 maximum)
Pomona
Electronics 5697
AI Gain Characteristic
Impedance: 50 Ω
BNC F-F-F T-Connector*
(quantity 0 minimum,
5 maximum)
Pomona
Electronics 3284
AI Gain Characteristic
Impedance: 50 Ω
*AI Gain verification and adjustment can be conducted one channel at a time, all six channels
simultaneously, as well as any number in between. The minimum quantity corresponds to one channel
at a time. The maximum quantity corresponds to all six channels simultaneously.
1 BNC Shorting Cap
2 InfiniBand 12X-6BNC Cable
3 PXIe-4480/4481
Table 2. Recommended Equipment (PXIe-4481) (Continued)
Equipment
Recommended
Model(s) Where Used
Minimum
Requirements
1
23

NI PXIe-4480/4481 Calibration Procedure |© National Instruments |7
Voltage Gain Accuracy Verification/Adjustment
Voltage gain verification and adjustment can be conducted one channel at a time, all six channels
simultaneously, as well as any number in between. Figure 2 illustrates the connections for
parallel channel operation, while Figure 3 illustrates the connections for sequential channel
operation.
Figure 2. Voltage Gain Accuracy/Flatness Connections (Six Channels)
Note Secure the cable to the module front panel using the cable connector
jackscrews.
1 Calibrator
2 Banana Plug Adapter
3 BNC Cable
4 BNC T-Connector
5 InfiniBand 12X-6BNC Cable
6 PXIe-4480/4481
1
32
6
5
4

8|ni.com |NI PXIe-4480//4481 Calibration Procedure
Figure 3. Voltage Gain Accuracy/Flatness Connections (One Channel)
Note Secure the cable to the module front panel using the cable connector
jackscrews.
1 Calibrator
2 Banana Plug Adapter
3 BNC Cable
4 InfiniBand 12X-6BNC Cable
5 PXIe-4480/4481
1
2
4 5
3

NI PXIe-4480/4481 Calibration Procedure |© National Instruments |9
Charge Gain Accuracy Verification/Adjustment
(PXIe-4480 only)
Charge gain verification and adjustment is conducted one channel at a time. Figure 4 illustrates
the connections for charge gain accuracy verification/adjustment.
Figure 4. Charge Gain Accuracy Connections
Note Secure the cable to the module front panel using the cable connector
jackscrews.
1 Calibrator
2 Banana Plug Adapter
3 10-32 to BNC Interface Cable
4 Calibration Capacitor
5 BNC Cable
6 InfiniBand 12X-6BNC Cable
7 PXIe-4480
1
2
3
6 7
54

10 |ni.com |NI PXIe-4480//4481 Calibration Procedure
IEPE Current Accuracy Verification (PXIe-4480 only)
Figure 5 illustrates the connections for IEPE current accuracy verification.
Figure 5. IEPE Current Accuracy Connections
Note Secure the cable to the module front panel using the cable connector
jackscrews.
1 Digital Multimeter
2 Banana Plug Adapter
3 BNC Cable
4 InfiniBand 12X-6BNC Cable
5 PXIe-4480
1
4 5
32

NI PXIe-4480/4481 Calibration Procedure |© National Instruments |11
Timebase Accuracy Verification/Adjustment
Figure 6 illustrates the connections for timebase accuracy verification/adjustment.
Figure 6. Timebase Accuracy Connections
Note Secure the cable to the module front panel using the cable connector
jackscrews.
1 Function Generator
2 BNC Cable
3 BNC Shorting Cap
4 InfiniBand 12X-6BNC Cable
5 PXIe-4480/4481
3
2
4 5
1

12 |ni.com |NI PXIe-4480//4481 Calibration Procedure
Test Conditions
The following setup and environmental conditions are required to ensure the PXIe-4480/4481
meets published specifications.
• Keep connections to the PXIe-4480/4481 as short as possible. Long cables and wires act as
antennas, picking up extra noise that can affect measurements.
• Verify that all connections to the device are secure.
• Maintain an ambient temperature of 23 °C ±5 °C. The device temperature will be greater
than the ambient temperature.
• Keep relative humidity below 80%.
• Allow a warm-up time of at least 15 minutes to ensure that the PXIe-4480/4481
measurement circuitry is at a stable operating temperature.
• Allow adequate warm-up time for all of the instruments and equipment according to the
manufacturer instructions.
Initial Setup
Refer to the DAQ Getting Started Guide and the PXIe-4480/4481 Getting Started Guide for
information about how to install the software and hardware and how to configure the device in
Measurement & Automation Explorer (MAX).
Note When a device is configured in MAX, it is assigned a device name. Each
function call uses this device name to determine which device to calibrate. This
document uses Dev_name to refer to the device name. In the following procedures,
use the device name as it appears in MAX.
Verification
The following performance verification procedures describe the sequence of operation and
provide test points required to verify the PXIe-4480/4481. The verification procedures assume
that adequate traceable uncertainties are available for the calibration references.
Voltage Input Performance Verification
This section verifies the voltage input performance of the PXIe-4480/4481. Some, but not all,
performance characteristics are affected by adjustment and are subject to reverification after adjustment.
Characteristics affected by adjustment have As Left test limits in addition to As Found test limits.
Characteristics unaffected by adjustment solely have test limits with no additional qualification.

NI PXIe-4480/4481 Calibration Procedure |© National Instruments |13
Voltage Offset Accuracy Verification
Complete the following steps to verify the voltage offset accuracy:
1. Using the equipment described in Table 1 (PXIe-4480) or Table 2 (PXIe-4481), connect the
module as shown in Figure 1.
2. Create and configure an AI voltage task on the device as shown in Table 3.
3. Start the task.
4. Acquire readings with the PXIe-4480/4481.
5. On a per channel basis, average all of the acquired samples.
6. Stop and clear the task.
7. Compare the averaged values to the appropriate limits in Table 4. The average is the offset
of the 10 V range.
8. Repeat steps 2 through 7 for each range of the device. When performing step 2, set the
range parameter to 5, 1, and 0.5 as required.
Table 3. Voltage Offset Accuracy Verification Configuration
Configuration Value
Physical channels Dev_name/ai0:5
Range 10 (V)
Coupling DC
Terminal configuration Pseudodifferential
Acquisition mode Finite number of samples
Sample rate 102,400
Samples per channel 102,400
Table 4. Voltage Offset Accuracy Limits
Range (V)
As Found Test Limit As Left Test Limit
Lower Limit
(mV)
Upper Limit
(mV)
Lower Limit
(mV)
Upper Limit
(mV)
10 -5.0 5.0 -0.2 0.2
5-2.2 2.2 -0.1 0.1
1-0.8 0.8 -0.05 0.05
0.5 -0.65 0.65 -0.05 0.05

14 |ni.com |NI PXIe-4480//4481 Calibration Procedure
Voltage Gain Accuracy Verification
Complete the following steps to verify the voltage gain accuracy:
1. Using the equipment described in Table 1 (PXIe-4480) or Table 2 (PXIe-4481), connect the
module to the calibrator as shown in Figure 2 (six channels) or Figure 3 (analog input
channel 0).
2. Configure the calibrator to generate an output with the amplitude and frequency listed in
the 10 V row of Table 5.
3. Create and configure an AI voltage task on the device as shown in Table 6.
4. If the coupling changes from DC to AC (for example, on the first gain verification point
tested), commit the configuration using the DAQmx Control Task VI and wait 5 seconds
for the input to settle. Subsequent gain verification points, which do not change the
coupling, do not require a delay.
5. Start the task.
6. Acquire readings with the PXIe-4480/4481.
Table 5. Voltage Gain Accuracy Limits
Range
(V)
Calibrator Output As Found Test Limit As Left Test Limit
Amplitude
(Vrms)
Frequency
(Hz)
Lower
Limit
(Vrms)
Upper
Limit
(Vrms)
Lower
Limit
(Vrms)
Upper
Limit
(Vrms)
10 6.3 1,000 6.2638 6.3364 6.29748 6.30252
53.15 1,000 3.1319 3.1682 3.14874 3.15126
10.63 1,000 0.62638 0.63364 0.62975 0.63025
0.5 0.315 1,000 0.31319 0.31682 0.31487 0.31513
Table 6. Voltage Gain Accuracy Verification Configuration
Configuration Value
Physical channel Dev_name/ai0 or Dev_name/ai0:5
Range 10 (V)
Coupling AC
Terminal configuration Pseudodifferential
Acquisition mode Finite number of samples
Sample rate 102,400
Samples per channel 102,400

NI PXIe-4480/4481 Calibration Procedure |© National Instruments |15
7. Calculate the RMS amplitude of the acquired fundamental harmonic. Compare this
amplitude to the appropriate voltage limits in Table 5. The calculated amplitude is used to
verify the gain accuracy of the measured analog input channels at the 10 V range setting.
As an example, you can use the Extract Single Tone Information VI to help calculate RMS.
Note that the output of this VI is peak amplitude, and you must divide the result by √2 to
convert to RMS.
8. Stop and clear the task.
9. Repeat steps 2 through 8 for each range setting of the device. When performing step 2,
configure the calibrator output to the amplitude and frequency indicated for the range to be
verified. When performing step 3, set the range parameter to 5, 1, and 0.5 as required.
10. If necessary, repeat steps 1 through 9 for all input channels of the device. In step 1, connect
the output of the calibrator to the channel being verified. In step 3, replace ai0 in the
physical channel parameter with the channel being verified.
Voltage Gain Flatness Verification
Note This performance characteristic is not affected by adjustment. Consequently,
reverification after adjustment is not necessary.
Note DC-coupled gain flatness is inherently better than AC-coupled gain flatness,
specifically at low frequencies. Consequently, the verification of AC-coupled gain
flatness covers both configurations.
Complete the following steps to verify the voltage gain flatness:
1. Using the equipment described in Table 1 (PXIe-4480) or Table 2 (PXIe-4481), connect the
module to the calibrator as shown in Figure 2 (six channels) or Figure 3 (analog input
channel 0).
2. Configure the calibrator to generate an output with the amplitude and frequency listed in
the 10 V row of Table 7.
Table 7. Voltage Gain Flatness Inputs
Range (V)
Calibrator Output
Amplitude (Vrms)Frequency (Hz)
10 6.3 1,000
53.15 1,000
10.63 1,000
0.5 0.315 1,000

16 |ni.com |NI PXIe-4480//4481 Calibration Procedure
3. Create and configure an AI voltage task on the device as shown in Table 8.
4. Start the task.
5. Acquire readings with the PXIe-4480/4481.
6. Calculate the RMS amplitude of the acquired fundamental harmonic. The measured
amplitude represents V1kHz of the measured analog input channels referenced in Table 9 at
the 10 V range setting.
As an example, you can use the Extract Single Tone Information VI to help calculate RMS.
Note that the output of this VI is peak amplitude, and you must divide the result by √2 to
convert to RMS.
7. Stop and clear the task.
8. Repeat steps 2 through 7 for each row in Table 9. When performing step 2, instead of
1 kHz, configure the calibrator output to the frequency listed in Table 9. The calibrator
output amplitude remains constant. Compare this amplitude to the appropriate limits in
Table 9.
Note The value of V1kHz is the measured amplitude of the 1 kHz tone, not the
nominal amplitude listed in Table 7.
9. Repeat steps 2 through 8 for each range setting of the device. When performing step 2,
configure the calibrator output to the amplitude and frequency indicated for the range to be
verified. When performing step 3, set the range parameter to 5, 1, and 0.5 as required.
Table 8. Voltage Gain Flatness Verification Configuration
Configuration Value
Physical channel Dev_name/ai0 or Dev_name/ai0:5
Range 10 (V)
Coupling AC
Terminal configuration Pseudodifferential
Acquisition mode Finite number of samples
Sample rate 1,250,000
Samples per channel 625,000

NI PXIe-4480/4481 Calibration Procedure |© National Instruments |17
10. If necessary, repeat steps 1 through 9 for all input channels of the device. In step 1, connect
the output of the calibrator to the channel being verified. In step 3, replace ai0 in the
physical channel parameter with the channel being verified.
Charge Input Performance Verification (PXIe-4480 only)
This section verifies the charge input performance of the PXIe-4480.
Charge Gain Accuracy Verification
Complete the following steps to verify the charge gain accuracy.
1. Using the equipment described in Table 1, connect analog input channel 0 of the module to
the calibrator as shown in Figure 4. Record the exact value of the calibrator capacitor,
which is printed on its label or provided on its calibration certificate. In this procedure, this
value is termed CCAL.
2. Configure the calibrator to generate an output with the amplitude and frequency listed in
the 20,000 pC row of Table 10.
Note While the calibrator output is voltage, its application through the series
calibration capacitor creates an effective charge input (QCAL = VCAL * CCAL). For
example, 6.3 Vrms applied through 1000 pF creates a charge input of 6300 pCrms.
Table 9. Voltage Gain Flatness Limits
Calibrator
Output
Frequency
(Hz)
Test Limit
(10 V, 5 V ranges)
Test Limit
(1 V range)
Test Limit
(0.5 V range)
Lower
Limit
(Vrms)
Upper
Limit
(Vrms)
Lower
Limit
(Vrms)
Upper
Limit
(Vrms)
Lower
Limit
(Vrms)
Upper
Limit
(Vrms)
40 0.9992 *
V1kHz
1.0008 *
V1kHz
0.9992 *
V1kHz
1.0008 *
V1kHz
0.9991 *
V1kHz
1.0009 *
V1kHz
20,000 0.9992 *
V1kHz
1.0008 *
V1kHz
0.9992 *
V1kHz
1.0008 *
V1kHz
0.9991 *
V1kHz
1.0009 *
V1kHz
50,000 0.9985 *
V1kHz
1.0015 *
V1kHz
0.9982 *
V1kHz
1.0018 *
V1kHz
0.9971 *
V1kHz
1.0029 *
V1kHz
100,000 0.9965 *
V1kHz
1.0035 *
V1kHz
0.9935 *
V1kHz
1.0066 *
V1kHz
0.9892 *
V1kHz
1.0109 *
V1kHz
200,000 0.9874 *
V1kHz
1.0127 *
V1kHz
0.9750 *
V1kHz
1.0257 *
V1kHz
0.9594 *
V1kHz
1.0423 *
V1kHz

18 |ni.com |NI PXIe-4480//4481 Calibration Procedure
3. Create and configure an AI charge task on the device as shown in Table 11.
4. Start the task.
5. Acquire readings with the PXIe-4480.
6. Calculate the RMS amplitude of the acquired fundamental harmonic. Compare this
amplitude to the appropriate charge limits in Table 10. The calculated amplitude is used to
verify the gain accuracy of the measured analog input channel at the 20,000 pC range
setting.
Table 10. Charge Gain Accuracy Limits
Range
(pC)
Calibrator Output As Found Test Limit As Left Test Limit
Amplitude
(Vrms)
Frequency
(Hz)
Lower
Limit
(pCrms)
Upper
Limit
(pCrms)
Lower
Limit
(pCrms)
Upper
Limit
(pCrms)
20,000 6.3 1,000 6.3 V *
CCAL *
0.9886
6.3 V *
CCAL *
1.0116
6.3 V *
CCAL *
0.995
6.3 V *
CCAL *
1.005
10,000 6.3 1,000 6.3 V *
CCAL *
0.9886
6.3 V *
CCAL *
1.0116
6.3 V *
CCAL *
0.995
6.3 V *
CCAL *
1.005
2,000 1.26 1,000 1.26 V *
CCAL *
0.9886
1.26 V *
CCAL *
1.0116
1.26 V *
CCAL *
0.995
1.26 V *
CCAL *
1.005
1,000 0.63 1,000 0.63 V *
CCAL *
0.9886
0.63 V *
CCAL *
1.0116
0.63 V *
CCAL *
0.995
0.63 V *
CCAL *
1.005
Table 11. Charge Gain Accuracy Verification Configuration
Configuration Value
Physical channel Dev_name/ai0
Measurement type Charge
Range 20,000 (pC)
Acquisition mode Finite number of samples
Sample rate 102,400
Samples per channel 102,400

NI PXIe-4480/4481 Calibration Procedure |© National Instruments |19
As an example, you can use the Extract Single Tone Information VI to help calculate RMS.
Note that the output of this VI is peak amplitude, and you must divide the result by √2 to
convert to RMS.
7. Stop and clear the task.
8. Repeat steps 2 through 7 for each range setting of the device. When performing step 2,
configure the calibrator output to the amplitude and frequency indicated for the range to be
verified. When performing step 3, set the range parameter to 10,000; 2,000; and 1,000 as
required.
9. Repeat steps 1 through 8 for all input channels of the device. In step 1, connect the output
of the calibrator to the channel being verified. In step 3, replace ai0 in the physical
channel parameter with the channel being verified.
IEPE Current Accuracy Verification (PXIe-4480 only)
Note This performance characteristic is not affected by adjustment. Consequently,
reverification after adjustment is not necessary.
Note During the IEPE verification, the Active LED on the device front panel will
illuminate RED, indicating a fault condition. This is an expected condition, and the
validity of the verification is unaffected. This is a result of the DMM’s low resistance
tripping the IEPE’s short detection monitor.
Complete the following steps to verify the IEPE current accuracy:
1. Set the digital multimeter to DC Current mode and a range suitable to measure currents
between 4 mA and 20 mA.
2. Using the equipment described in Table 1, connect the Current input of the digital
multimeter to the analog input channel 0 of the device.
3. Create and configure an AI voltage task on the device as shown in Table 12.
4. Start the task.
Table 12. IEPE Current Accuracy Verification Configuration
Configuration Value
Physical channel Dev_name/ai0
Range 10 (V)
Coupling AC
Terminal configuration Pseudodifferential
Excitation (IEPE) 0.004 (A)
Acquisition mode Finite number of samples
Sample rate 102,400
Samples per channel 10,240