National Instruments SC Express PXIe-4330 Manual

CALIBRATION PROCEDURE
PXIe-4330/4331
This document contains information about verifying and adjusting National Instruments
PXIe-4330/4331 modules using NI-DAQmx 9.1 and later. For more information about
calibration, visit ni.com/calibration.
Contents
Software.................................................................................................................................... 2
Documentation.......................................................................................................................... 2
Calibration Interval................................................................................................................... 2
Test Equipment......................................................................................................................... 3
Test Conditions......................................................................................................................... 4
Calibration Procedure ............................................................................................................... 4
Initial Setup....................................................................................................................... 5
Connecting the Equipment ............................................................................................... 5
Install the CAL-4330 Into a Rack (Optional)........................................................... 7
Connect the Calibration and Switch Cables ............................................................. 8
Connect the DMM and Multifunction Calibrator Cables......................................... 10
Verification Procedures .................................................................................................... 11
Gain Accuracy Verification...................................................................................... 11
Input Offset Verification .......................................................................................... 14
Shunt Quarter-Bridge Calibration Accuracy Verification........................................ 15
Shunt Calibration Resistance Accuracy Verification ............................................... 17
Excitation Voltage Verification................................................................................ 18
Gain and Offset Adjustment Procedure............................................................................ 20
Test Limits................................................................................................................................ 24
Gain Accuracy Test Limits............................................................................................... 25
Input Offset Test Limits ................................................................................................... 31
Shunt Quarter-Bridge Calibration Test Limits ................................................................. 32
Shunt Calibration Resistance Test Limits ........................................................................ 32
Excitation Voltage Test Limits......................................................................................... 33
Appendix A: Connection Path Details...................................................................................... 34
Worldwide Support and Services ............................................................................................. 40

2|ni.com |PXIe-4330/4331 Calibration Procedure
Software
Install NI-DAQmx 9.1 or later on the calibration computer. NI-DAQmx includes high-level
function calls to simplify the task of writing software to calibrate modules. You must have the
proper module driver installed on the calibration system before calibrating the module.
Note NI recommends that you install the NI-DAQmx driver software before
physically installing the PXIe-4330/4331. NI-DAQmx, available at ni.com/
downloads, configures and controls the PXIe-4330/4331.
NI-DAQmx supports a number of programming languages, including LabVIEW,
LabWindows™/CVI™, C/C++, C#, and Visual Basic .NET.
Documentation
The following documents are your primary references for writing your calibration utility with
NI-DAQmx. You can download the latest version of these documents from the NI Web site at
ni.com/manuals.
•TheNI SC Express 4330/4331 Installation Guide and Terminal Block Specifications
provides instructions for installing and configuring the NI PXIe-4330/4331 module.
•TheNI PXIe-4330/4331 User Manual describes how to use the NI PXIe-4330/4331.
•TheNI PXIe-4330/4331 Specifications lists the specifications for the NI PXIe-4330/4331.
•TheNI-DAQmx Help includes information about creating applications that use the
NI-DAQmx driver.
•TheNI-DAQmx C Reference Help includes information about the functions in the driver.
Calibration Interval
National Instruments recommends a calibration interval of one year for the PXIe-4330/4331.
Adjust and verify the PXIe-4330/4331 at the recommended calibration interval based on the
measurement accuracy demands of your application.

PXIe-4330/4331 Calibration Procedure |© National Instruments |3
Test Equipment
National Instruments recommends that you use the equipment in Table 1 for calibrating an
PXIe-4330/4331 module.
Table 1. Recommended Equipment
Equipment Recommended Model(s) Requirements
Multifunction
calibrator
Fluke 5520A If this instrument is unavailable, use a
calibrator that can provide resistance values
in the range of 120 Ωto 1 k Ωwith 0.01 Ω
resolution, an accuracy of 90 ppm or better,
automatic lead wire compensation, and
2-wire output compensation.
DMMs (x2) PXI-4071 If this instrument is unavailable, use
multiranging 6 1/2 digit DMMs with a DC
voltage accuracy of 40 ppm or better of
reading +6 ppm of range for the 10 V and
1 V ranges, and 4-wire resistance
measurement capability with resistance
accuracy of 80 ppm or better of reading
+6 ppm range for the 100 k Ωrange
Chassis PXIe-1062Q If this chassis is unavailable, use another
PXIe chassis
Switch modules (x2) PXIe-2737 4x64 2-wire relay module
160-Pin DIN to
160-Pin DIN cable
for PXIe-2737 (x2)
NI Part Number: 782417-02 Cable for connecting the PXIe-2737s to the
CAL-4330
CAL-4330 to
PXIe-4330/4331
calibration cable
NI Part Number: 787003-01 Cable and included standoffs for connecting
the PXIe-4330/4331 DUT to the CAL-4330
Connection
accessory
CAL-4330, NI Part Number
786988-01
Calibration Fixture to enable automated
calibration of the PXIe-4330/4331
Banana-to-banana
patch cables (x10)
Five Pomona 1440-36-0 black
banana plug patch cords
(cables)
Five Pamona 1440-36-1 red
banana plug patch cords
(cables)
—

4|ni.com |PXIe-4330/4331 Calibration Procedure
Test Conditions
The following setup and environmental conditions are required to ensure the NI device meets
published specifications.
• Keep connections to the module as short as possible. Long cables and wires act as antennae,
picking up extra noise that can affect measurements.
• Use shielded copper wire for all cable connections to the module. Use twisted-pair wire to
eliminate noise and thermal offsets.
• Maintain an ambient temperature of 23 °C ±5 °C.
• Keep relative humidity below 80%.
• Allow a warm-up time of at least 15 minutes to ensure that the measurement circuitry is at
a stable operating temperature.
• Ensure that the PXI Express chassis fan speed is set to HIGH, that the fan filters are clean,
and that the empty slots contain filler panels. For more information, refer to the Maintain
Forced-Air Cooling Note to Users document available at ni.com/manuals.
• Warm-up time for test equipment may vary depending on the manufacturer. Please refer to
the equipment’s Operators Manual for specified warm-up time.
• To meet Fluke 5520A specifications, zero the Calibrator every 7 days, or when the
Calibrator ambient temperature changes by more than 5 °C. Warm-up time for Fluke 5520A
is 30 minutes.
Calibration Procedure
This section provides instructions for verifying the performance of the PXIe-4330/4331.
The calibration process consists of the following steps:
1. Initial Setup—Install the module and configure it in Measurement & Automation Explorer
(MAX).
2. Verification Procedures—Verify the existing operation of the module. This step confirms
whether the module is operating within the published specifications—gain accuracy, input
offset, shunt quarter-bridge calibration, shunt calibration resistance, and excitation—prior
to adjustment.
3. Gain and Offset Adjustment Procedure—If necessary, perform an external calibration that
adjusts the module calibration constants with respect to a known calibration source.
4. Reverification—Repeat the verification procedure to ensure that the module is operating
within the published specifications after adjustment.

PXIe-4330/4331 Calibration Procedure |© National Instruments |5
Initial Setup
You must configure the module in MAX to communicate with NI-DAQmx.
Complete the following steps to configure a module in MAX. Refer to the
NI SC Express 4330/4331 Installation Guide and Terminal Block Specifications for complete
installation instructions.
1. Install the NI-DAQmx, 9.1 or later, driver software.
Caution Always have the PXI Express chassis turned off when inserting a module.
2. Insert the module into an available slot in the PXI Express chassis.
3. Power on the chassis.
4. Launch MAX.
5. Expand Devices and Interfaces to confirm that MAX detects the module.
6. Right-click the module name and select Self-Test to ensure that the module is working
properly.
Note When a module is configured with MAX, it is assigned a module name. Each
function call uses this module name to determine which DAQ module to calibrate.
This document uses Dev1 to refer to the module name. In the following procedures,
use the module name as it appears in MAX.
Connecting the Equipment
The CAL-4330 and two switch modules provide the ability to programmatically connect the
required module connections as needed for the various verification and calibration steps.
Refer to the specific verification or calibration procedure section for information describing the
required switch connections. Detailed connection paths for each of the verification calibration
steps are shown in Appendix A: Connection Path Details. Before connecting or disconnecting
the calibrator from the module, always set the calibrator to standby mode (STBY).

6|ni.com |PXIe-4330/4331 Calibration Procedure
Refer to Figure 1 for a block diagram of the equipment connections. Figure 2 and Figure 3 show
the front and rear connectors on the CAL-4330.
Figure 1. Block Diagram
Figure 2. Front Connectors
Figure 3. Rear Connectors
1SWITCH1 2SWITCH2 3 DEVICE UNDER TEST
1DMM2 2DMM1 3CALIBRATOR
CAL-4330
2-wire
4x64 Switch
2-wire
4x64 Switch
PXIe-4330 or
PXIe 4331
HI
DMM 2
LO
SENSE HI
SENSE LO
HI
LO
DMM 1
VOLTSHI
CALIBRATOR
VOLTSLO
AUX HI
AUX LO
SWITCH 1
SWITCH 2
DUT
CAL-4330
SWITCH 1 SWITCH 2
DEVICE UNDER TEST
PXIe-4330/4331
23 1
DMM 2 DMM 1
CAL-4330
CALIBRATOR
SENSE
LO HI
AUX
LO HI
VOLTS
LO HI
VOLTS
LO HI
VOLTS
LO HI
23
1

PXIe-4330/4331 Calibration Procedure |© National Instruments |7
Install the CAL-4330 Into a Rack (Optional)
To install the CAL-4330 into a rack, complete the following steps:
1. Attach the two rack-mount brackets to the sides of the CAL-4330. The brackets and screws
are included with the CAL-4330.
Figure 4. Using the Rack-Mount Brackets
2. Place the CAL-4330 in the desired position in your rack.
3. Install and tighten the four rack-mounting screws that are included with the CAL-4330.
If the chassis is not already installed in the rack (optional), complete the following steps:
1. Attach the PXIe chassis rack-mount hardware to the PXIe chassis. Refer to your
rack-mount kit installation guide for more details.
2. Mount the PXIe chassis in the rack in the desired position. Refer to your rack-mount kit
installation guide for more details.
1 CAL-4330
2 Rack-Mount Brackets (2)
3 Rack-Mount Bracket Mounting Screws (4)
4 Rack-Mounting Screws (4)
SWITCH 1 SWITCH 2 DEVICEUNDER TEST
PXIe-4330/4331
CAL-4330
4
2
3
2
1

8|ni.com |PXIe-4330/4331 Calibration Procedure
Connect the Calibration and Switch Cables
Figure 5. Connecting the Calibration Cable
1. Screw the two standoffs into the PXIe-4330/4331 module and tighten the standoffs to
1.30 N · m (11.5 lb · in.), as shown in Figure 5.
2. Connect the male end of the calibration cable to the CAL-4330 and tighten the two jack
screws to 0.90 N · m (8.0 lb · in.), as shown in Figure 5.
3. Connect the female end of the calibration cable to the PXIe-4330/4331 and tighten the two
jack screws to 0.90 N · m (8.0 lb · in.), as shown in Figure 5.
1CAL-4330
2 PXI Chassis
3 PXIe-4330/4331 (DUT)
4 Standoffs (2)
5 Jack Screws (2)
6 CAL-4330 to PXIe-4330/4331 Calibration Cable
7 Jack Screws (2)
NI PXIe-1062Q
NI PXIe-1062Q
COOLINGCLEARANCEANDFANFILTERMAINTENANCEREQUIRED.SEEMANUAL.
COOLING CLEARANCEANDFANFILTERMAINTENANCEREQUIRED. SEEMANUAL.
SWITCH 1SWITCH 2DEVICEUNDERTEST
PXIe-4330/4331
CAL-4330
7
1
2
4
5
6
3

PXIe-4330/4331 Calibration Procedure |© National Instruments |9
4. Connect the two 160-Pin DIN to 160-Pin DIN cables from the CAL-4330 to the two
PXIe-2737 modules and tighten all the jack screws to 0.56 N · m (5.0 lb · in.), as shown in
Figure 6 and Figure 7.
Figure 6. Connecting the Switch 2 Cable
Figure 7. Connecting the Switch 1 Cable
NIPXIe-1062Q
NIPXIe-1062Q
COOLINGCLEARANCEANDFANFILTERMAINTENANCEREQUIRED.SEEMANUAL.
COOLINGCLEARANCEANDFANFILTERMAINTENANCEREQUIRED.SEEMANUAL.
150V
150V
150V
150V
NI PXIe-1062Q NIPXIe-1062Q
COOLING CLEARANCEANDFANFILTERMAINTENANCEREQUIRED.SEEMANUAL. COOLINGCLEARANCEANDFANFILTERMAINTENANCEREQUIRED.SEEMANUAL.
150V150V
150V 150V
150V150V
150V 150V

10 |ni.com |PXIe-4330/4331 Calibration Procedure
Connect the DMM and Multifunction Calibrator Cables
1. Connect DMM 1 on the back of the CAL-4330 to a PXI-4071 as shown in Figure 8.
Figure 8. DMM 1
2. Connect DMM 2 on the back of the CAL-4330 to another PXI-4071 as shown in Figure 9.
Figure 9. DMM 2
1CAL-4330 2PXI-4071
1CAL-4330 2PXI-4071
HI
LO
300 V
MAX
CATII
HI
LO
AUX I/O
1 A
250 V
MAX
300 V
MAX
CATII
5 V
MAX
AMPS
INPUT
V˖
SENSE
˖4W
NI PXI-4071
6½-Digit FlexDMM
VOLTS
DMM 1
LO HI
2
1
HI
LO
300 V
MAX
CATII
HI
LO
AUX I/ O
1 A
250 V
MAX
300 V
MAX
CATII
5 V
MAX
AMPS
INPUT
V˖
SENSE
˖4W
NI PXI-4071
6½-Digit FlexDMM
SENSE
DMM 2
LO HI
VOLTS
LO HI
1
2

PXIe-4330/4331 Calibration Procedure |© National Instruments |11
3. Connect the CALIBRATOR on the back of the CAL-4330 to a Fluke 5520A multifunction
calibrator as shown in Figure 10.
Figure 10. CALIBRATOR
Verification Procedures
This section provides instructions for verifying the PXIe-4330/4331 specifications. The
PXIe-4330/4331 has eight independent analog input channels. You can conduct verification on
any or all of them, depending upon your desired test coverage.
You can verify the following for PXIe-4330/4331 modules:
•Gain Accuracy Verification
•Input Offset Verification
•Shunt Quarter-Bridge Calibration Accuracy Verification
•Shunt Calibration Resistance Accuracy Verification
•Excitation Voltage Verification
Gain Accuracy Verification
This section provides instructions for verifying the PXIe-4330/4331 gain accuracy
specifications. Table 8 shows all the settings for the PXIe-4330/4331. Throughout the gain
accuracy verification, use Tables 12 through 23 to determine if the module is operating within
its specified range.
Complete the following steps to test the gain accuracy of the module.
1. Configure the switch modules to connect to the 350 Ωbridge completion resistor on the
CAL-4330. Refer to Table 2 for the specific switch column and row configuration. The
connection paths are shown in Figure 11 in Appendix A: Connection Path Details.
2. Measure the 350 Ωbridge completion resistor with DMM 2 configured for 4-wire
resistance with offset ohms compensation enabled. Divide the measured resistance by 350
and record the result as Radj.
1 CAL-4330 2 Fluke 5520A
AUX
CALIBRATOR
LO HI
VOLTS
LO HI
AUX
A, ˖-SENSE, AUX V
20A
TC
GUARD
20 V PK MAX
HI
20V
RMS
MAX
1V PK
MAX
20V
RMS
MAX
1000V
RMS
MAX LO
NORMAL
V, ˖, , RTD
2
1

12 |ni.com |PXIe-4330/4331 Calibration Procedure
3. Set the calibrator to standby mode (STBY).
4. Configure the switch modules to connect to the channel you want to verify. Refer to Table 3
for the specific switch column and row configuration. The connection paths are shown in
Figure 12 in Appendix A: Connection Path Details.
Note Only one channel can be connected to the calibrator at a time.
5. Zero the calibrator with the ohms-only zero (OHMS ZERO) operation. Refer to the
calibrator documentation for more information about zeroing the calibrator.
6. Set the calibrator output for 2-wire compensation (COMP 2-wire). This automatically
compensates for the lead wire resistance in series with the HI and LO terminals of the
calibrator.
7. Set the calibrator resistance output to a Calibrator Output value for the appropriate range
beginning with the 0 V/V nominal value, 350 Ω, indicated in Table 12 for excitation
voltages >2.5 V or Table 13 for excitation voltages ≤2.5 V for fs≤51.2 kHz. Use Tables 14
through 23 for fs> 51.2 kHz and their specific excitation voltages.
Table 2. Bridge Completion Resistor Measurement
Switch 1
r0->c2, r1->c55, r0->c8, r1->c9
Table 3. Gain Accuracy Verification Switch Settings
Channel Switch 1 Switch 2
0r0->c0,r1->c1,r0->c2,r1->c3,
r3->c7,r3->c16
r0->c0,r1->c1,r0->c2,r1->c3,
r0->c14,r1->c16
1r0->c0,r1->c1,r0->c2,r1->c3,
r3->c7,r3->c21
r0->c0,r1->c1,r0->c2,r1->c3,
r0->c19,r1->c21
2r0->c0,r1->c1,r0->c2,r1->c3,
r3->c7,r3->c26
r0->c0,r1->c1,r0->c2,r1->c3,
r0->c24,r1->c26
3r0->c0,r1->c1,r0->c2,r1->c3,
r3->c7,r3->c31
r0->c0,r1->c1,r0->c2,r1->c3,
r0->c29,r1->c31
4r0->c0,r1->c1,r0->c2,r1->c3,
r3->c7,r3->c36
r0->c0,r1->c1,r0->c2,r1->c3,
r0->c34,r1->c36
5r0->c0,r1->c1,r0->c2,r1->c3,
r3->c7,r3->c41
r0->c0,r1->c1,r0->c2,r1->c3,
r0->c39,r1->c41
6r0->c0,r1->c1,r0->c2,r1->c3,
r3->c7,r3->c46
r0->c0,r1->c1,r0->c2,r1->c3,
r0->c44,r1->c46
7r0->c0,r1->c1,r0->c2,r1->c3,
r3->c7,r3->c51
r0->c0,r1->c1,r0->c2,r1->c3,
r0->c49,r1->c51

PXIe-4330/4331 Calibration Procedure |© National Instruments |13
8. If this is the first test point, set the calibrator to operate mode (OPR) to enable the output.
9. Create a DAQmx task.
10. Create and configure an AI Bridge (V/V) channel.
11. Configure the properties for the acquisition as described in Table 8.
12. Commit the task to enable the latest excitation voltage.
13. Start the task.
14. Read 10,000 samples of data for fs= 25600. Read 40,000 samples of data for fs= 102400.
15. Average the readings that you acquired in step 14 and record the result as Test Result, which
is used in step 18.
16. Clear the task.
17. Repeat steps 7 through 16 for all calibrator output values. NI recommends that you verify
all values, although you can save time by verifying only the values used in your application.
18. Perform the following calculation for each test result value other than 0 V/V, using the
results you recorded in step 15.
19. Compare the compensated result (Vr) for each value to the Upper Limit (V/V) and Lower
Limit (V/V) values in Table 12 for excitation voltages >2.5 V or Table 13 for excitation
voltages ≤2.5 V for fs≤51.2 kHz. Use Tables 14 through 23 for fs> 51.2 kHz and the
excitation value specified in each table. If the result is between these values, the module
passes the test.
Note You can analyze data in V/V form or convert it to strain using the standard
quarter-bridge equation:
Note
where Vris the compensated reading from the PXIe-4330/4331 and GF is a gage
factor of 2.
20. If calibrating an NI PXIe-4331, repeat steps 7 through 19 using a sample rate of 102.4 kHz
and the appropriate test limits from Tables 14 through 23.
21. Repeat steps 7 through 20 for every excitation setting you want to verify.
22. Set the calibrator to standby mode (STBY).
23. Repeat steps 3 through 22 for every channel you want to verify.
24. Disconnect the calibrator from the module.
VrTest Result 0 V/V Test Result–=
strain ε()
4–Vr ×
GF 1 2 Vr ×()+()
-------------------------------------------=

14 |ni.com |PXIe-4330/4331 Calibration Procedure
Input Offset Verification
This section provides instructions for verifying the PXIe-4330/4331 input offset specifications.
Table 8 shows all settings for the PXIe-4330/4331. Throughout the input offset verification, use
Tables 24 and 25 to determine if the module is operating within its specified range.
Complete the following steps to test the input offset accuracy of the module.
1. Configure the switch modules to connect to the channel you want to verify. Refer to Table 4
for the specific switch column and row configuration. The connection paths are shown in
Figure 13 in Appendix A: Connection Path Details.
2. Create a DAQmx task.
3. Create and configure an AI Bridge (V/V) channel.
4. Configure the properties for the acquisition as described in Table 8.
5. Start the task.
6. Read 10,000 samples of data if fs= 25600. Read 40,000 samples of data if fs= 102400
7. Average the readings that you acquired and record the result.
8. Clear the task.
9. Compare the final result to the Upper Limit and Lower Limit values in Table 24 for fs≤
51.2 kHz and Table 25 for fs> 51.2 kHz. If the result is between these values, the module
passes the test.
Table 4. Offset Verify Switch Settings
Channel Switch 1 Switch 2
0r2->c4,r2->c11,r3->c12,
r3->c16
r0->c4,r1->c5,r0->c6,r1->c7,
r0->c14,r1->c16
1r2->c4,r2->c11,r3->c12,
r3->c21
r0->c4,r1->c5,r0->c6,r1->c7,
r0->c19,r1->c21
2r2->c4,r2->c11,r3->c12,
r3->c26
r0->c4,r1->c5,r0->c6,r1->c7,
r0->c24,r1->c26
3r2->c4,r2->c11,r3->c12,
r3->c31
r0->c4,r1->c5,r0->c6,r1->c7,
r0->c29,r1->c31
4r2->c4,r2->c11,r3->c12,
r3->c36
r0->c4,r1->c5,r0->c6,r1->c7,
r0->c34,r1->c36
5r2->c4,r2->c11,r3->c12,
r3->c41
r0->c4,r1->c5,r0->c6,r1->c7,
r0->c39,r1->c41
6r2->c4,r2->c11,r3->c12,
r3->c46
r0->c4,r1->c5,r0->c6,r1->c7,
r0->c44,r1->c46
0r2->c4,r2->c11,r3->c12,
r3->c51
r0->c4,r1->c5,r0->c6,r1->c7,
r0->c49,r1->c51

PXIe-4330/4331 Calibration Procedure |© National Instruments |15
10. If calibrating a PXIe-4331, repeat steps 2 through 9 using a sample rate of 102.4 kHz.
11. Repeat steps 1 through 10 for each channel you want to verify.
Shunt Quarter-Bridge Calibration Accuracy Verification
This section provides instructions for verifying the PXIe-4330/4331 shunt quarter-bridge
calibration accuracy. Table 10 shows all settings for the PXIe-4330/4331. Throughout the shunt
quarter-bridge calibration accuracy verification, use Table 26 to determine if the module is
operating within its specified range. If the module is not operating within the specified values,
refer to the Worldwide Support and Services section for assistance in returning the
PXIe-4330/4331 to NI.
Complete the following steps to test the accuracy of the module shunt quarter-bridge calibration.
1. Configure the switch modules to connect to the channel you want to verify. Refer to Table 5
for the specific switch column and row configuration. The connection paths are shown in
Figure 14 in Appendix A: Connection Path Details.
Note Only one channel can be connected to the calibrator at a time.
2. Set the calibrator output for 2-wire compensation (COMP 2-wire). This automatically
compensates for the lead wire resistance in series with the HI and LO terminals of the
calibrator.
3. Set the calibrator resistance output to 120 Ω, 350 Ω, or 1000 Ω, depending on the
quarter-bridge configuration you want to verify. This must match the configuration setting
made in step 7.
4. Set the calibrator to operate mode (OPR).
5. Create the DAQmx task.
6. Create and configure an AI Bridge (V/V) channel.
7. Configure the properties for the acquisition as described in Table 10.
Table 5. Shunt Quarter-Bridge Calibration Accuracy Verification
Channel Switch 1
0r1->c0,r0->c1,r1->c15,r3->c16,r0->c17,r3->c18
1r1->c0,r0->c1,r1->c20,r3->c21,r0->c22,r3->c23
2r1->c0,r0->c1,r1->c25,r3->c26,r0->c27,r3->c28
3r1->c0,r0->c1,r1->c30,r3->c31,r0->c32,r3->c33
4r1->c0,r0->c1,r1->c35,r3->c36,r0->c37,r3->c38
5r1->c0,r0->c1,r1->c40,r3->c41,r0->c42,r3->c43
6r1->c0,r0->c1,r1->c45,r3->c46,r0->c47,r3->c48
7r1->c0,r0->c1,r1->c50,r3->c51,r0->c52,r3->c53

16 |ni.com |PXIe-4330/4331 Calibration Procedure
8. Disable shunt calibration for the channel.
9. Commit the task to enable the latest excitation voltage.
10. Start the task.
11. Read 10,000 samples of data.
12. Average the readings that you acquired and record the result as ResultSCD.
13. Stop the task.
14. Set the shunt calibration resistance for the channel using the Shunt Cal A Resistor Value
property with one of the following values: 33,333 Ω, 50,000 Ω, or 100,000 Ω.
15. Enable shunt calibration for the channel.
16. Start the task.
17. Read 10,000 samples of data.
18. Average the readings that you acquired and record the result as ResultSCE.
19. Stop the task.
20. Perform the following calculation using the results you recorded in steps 12 and 18:
where ResultSCE = result with shunt calibration enabled in step 18
ResultSCD = result with shunt calibration disabled in step 12
21. Compare the final result (Vr) to the Upper Limit and Lower Limit values in Table 26. If the
result is between these values, the module passes the test.
Note You can analyze data in V/V form or convert it to strain using the standard
quarter-bridge equation:
where Vris the compensated reading from the PXIe-4330/4331 and GF is a gage
factor of 2.
22. Repeat steps 3 through 21 for each combination of quarter-bridge completion and shunt
calibration resistance settings you want to verify.
23. Set the calibrator to standby mode (STBY).
24. Repeat steps 1 through 23 for each channel you want to verify.
25. Disconnect the calibrator from the module.
VrResultSCE ResultSCD –=
strain ε()
4–Vr ×
GF 1 2 Vr ×()+()
-------------------------------------------=

PXIe-4330/4331 Calibration Procedure |© National Instruments |17
Shunt Calibration Resistance Accuracy Verification
This section provides instructions for verifying the PXIe-4330/4331 shunt resistance accuracy.
Table 10 shows all settings for the PXIe-4330/4331. Throughout the shunt resistance accuracy
verification, use Table 27 to determine if the module is operating within its specified range. If
the module is not operating within the specified values, refer to the Worldwide Support and
Services section for assistance in returning the terminal block to NI.
Complete the following steps to test the accuracy of the module shunt resistances.
1. Configure the switch modules to connect to the channel you want to verify. Refer to table 6
for the specific switch column and row configuration. The connection paths are shown in
Figure 15 in Appendix A: Connection Path Details.
2. Create the DAQmx task.
3. Create and configure an AI Bridge (V/V) channel.
4. Enable shunt calibration for the channel. Configure the properties for the acquisition as
described in Table 9.
5. Set the shunt calibration resistance for the channel using the Shunt Cal A Resistor Value
property with one of the following values: 33,333 Ω, 50,000 Ω, or 100,000 Ω.
6. Commit the task to enable the specified shunt resistor.
7. Take a reading of the shunt calibration resistance from the DMM using the 4-wire
measurement configuration and record the result.
8. Compare the result from step 7 to the Upper Limit and Lower Limit values in Table 27 for
the applicable resistance value. If the result is between these values, the module passes the
test.
9. Repeat steps 5 through 8 for each shunt calibration resistance you want to verify.
10. Clear the task.
11. Repeat steps 1 through 10 for each channel you want to verify.
12. Disconnect the DMM from the module.
Table 6. Shunt Resistance Accuracy Verification
Channel Switch 1
0r3->c8,r2->c9,r2->c14,r3->c15
1r3->c8,r2->c9,r2->c19,r3->c20
2r3->c8,r2->c9,r2->c24,r3->c25
3r3->c8,r2->c9,r2->c29,r3->c30
4r3->c8,r2->c9,r2->c34,r3->c35
5r3->c8,r2->c9,r2->c39,r3->c40
6r3->c8,r2->c9,r2->c44,r3->c45
7r3->c8,r2->c9,r2->c49,r3->c50

18 |ni.com |PXIe-4330/4331 Calibration Procedure
Excitation Voltage Verification
This section provides instructions for verifying the PXIe-4330/4331 excitation voltage
specifications. Table 28 in the Test Limits section shows all acceptable excitation voltage
settings for the PXIe-4330/4331. Throughout the excitation voltage verification, use Table 28 to
determine if the module is operating within its specified range.
Complete the following steps to test the performance of the module.
1. Configure the switch modules to connect to the channel you want to verify. Refer to Table 7
for the specific switch column and row configuration.The connection paths are shown in
Figure 16 in Appendix A: Connection Path Details.
2. Create the DAQmx task.
3. Create and configure an AI Bridge (V/V) channel.
4. Configure the properties for the task configuration as described in Table 8.
Note Set the sample rate and samples to read to 25,600 and 10,000 respectively for
the excitation voltage verification.
5. Commit the task.
6. Take a reading of the excitation voltage from the DMM and record the result.
7. Compare the result from step 6 to the Upper Limit and Lower Limit values indicated in
Table 28 for the applicable excitation setting.
8. Clear the task.
9. Repeat steps 2 through 8 for all excitation voltage settings.
10. Repeat steps 1 through 9 for all channels.
11. Disconnect the DMM from the module.
Table 7. Excitation Verify Switch Settings
Channel Switch 1 Switch 2
0r3->c4,r3->c6 r0->c8,r0->c14
1r3->c4,r3->c6 r0->c8,r0->c19
2r3->c4,r3->c6 r0->c8,r0->c24
3r3->c4,r3->c6 r0->c8,r0->c29
4r3->c4,r3->c6 r0->c8,r0->c34
5r3->c4,r3->c6 r0->c8,r0->c39
6r3->c4,r3->c6 r0->c8,r0->c44
7r3->c4,r3->c6 r0->c8,r0->c49

PXIe-4330/4331 Calibration Procedure |© National Instruments |19
Table 8. Configuration Settings for Full-Bridge Operation
Property Value
Channel Name Use channel names specific to your application.
Acquisition Mode Finite number of samples
Rate (Hz) 25,600 or 102,400*
Samples to Read 10,000 or 40,000†
Measurement Type Bridge
Max Input Limit 0.025 or 0.10**
Min Input Limit -0.025 or -0.10**
Units V/V
Bridge Type Full Bridge
Nominal Bridge Resistance 350 Ω
Vex Sour c e Internal
Vex Value 0.625, 1.0, 1.5, 2.0, 2.5, 2.75, 3.3, 5.0, 7.5, or 10.0*
* Use the excitation value and rate that corresponds to the configuration being verified.
† Read 10,000 samples when verifying at the 25,600 Hz rate. Read 40,000 samples when verifying at the
102,400 Hz rate.
** Use -0.025 and 0.025 for excitation >2.5 V. Use -0.10 and 0.10 for excitation ≤2.5 V.
Table 9. Configuration Settings for Shunt Calibration Resistance
Accuracy Verification
Property Value
Channel Name Use channel names specific to your application.
Acquisition Mode Finite number of samples
Rate (Hz) 25,600
Samples to Read 10,000
Measurement Type Bridge
Max Input Limit 0.10
Min Input Limit -0.10
Units V/V
Bridge Type Full Bridge
Nominal Bridge Resistance 350 Ω

20 |ni.com |PXIe-4330/4331 Calibration Procedure
Gain and Offset Adjustment Procedure
Use the adjustment procedure to adjust the gain and offset calibration constants for each channel
and excitation. At the end of each calibration procedure, these new constants are stored in the
external calibration area of the EEPROM.
Complete the following steps to perform module adjustment.
1. Configure the switch modules to connect to the channel you want to verify. Refer to
Table 11 for the specific switch column and row configuration.The connection paths are
shown in Figure 17 in Appendix A: Connection Path Details.
Vex Source Internal
Vex Value 2.5
Table 10. Configuration Settings for Quarter-Bridge Operation
Property Value
Channel Name Use channel names specific to your application.
Acquisition Mode Finite number of samples
Rate (Hz) 25,600
Samples to Read 10,000
Measurement Type Bridge
Max Input Limit 0.10
Min Input Limit -0.10
Units V/V
Bridge Type Quarter Bridge
Nominal Bridge Resistance 120 Ω, 350 Ω, 1 kΩ∗
Vex Source Internal
Vex Value 2.5
*Use the bridge resistance value that corresponds to the configuration being verified.
Table 9. Configuration Settings for Shunt Calibration Resistance
Accuracy Verification (Continued)
Property Value