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NI 5122/5124 Calibration Procedure

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Introduction

This document contains instructions for calibrating NI PXI/PCI-5122 and 
NI PXI/PCI-5124 digitizers. This calibration procedure is intended for 
metrology labs. This document describes specific programming steps for 
writing an external calibration procedure for the NI 5122/5124.

The NI 5122/5124 supports two types of calibration: self-calibration (or 
internal calibration) and external calibration.

Summary of Contents for 5124

Page 1: ...ons 8 Complete Calibration 9 Optional Calibration 10 External Calibration Requirements 12 Test Equipment 12 Test Conditions 12 External Calibration Procedures 13 Verifying NI 5122 5124 Specifications 13 Vertical Offset and Vertical Gain Accuracy 13 Programmable Vertical Offset Accuracy 20 Timing Accuracy 22 Bandwidth and Flatness 24 Trigger Sensitivity 29 Adjusting the NI 5122 5124 31 Calibration ...

Page 2: ...ms and dialog box options Bold text also denotes parameter names italic Italic text denotes variables emphasis a cross reference or an introduction to a key concept This font also denotes text that is a placeholder for a word or value that you must supply monospace Text in this font denotes text or characters that you should enter from the keyboard sections of code programming examples and syntax ...

Page 3: ...elf calibration can be performed as necessary to compensate for environmental changes Caution Although you can use self calibration repeatedly self calibrating the NI 5122 5124 more than a few times a day may cause excessive wear on the relays over time The measurement accuracy requirements of your application determine how often you should externally calibrate the NI 5122 5124 NI recommends that ...

Page 4: ...tion Reference Help or the NI SCOPE VI Reference Help These references can be found in the NI High Speed Digitizers Help To access this help file go to Start Programs National Instruments NI SCOPE Documentation NI High Speed Digitizers Help Table 1 Calibration File Locations after Installing NI SCOPE 2 7 or Later File Name and Location Description IVI Bin niscope_32 dll NI SCOPE driver containing ...

Page 5: ...curacy of these internal calibration circuits with another instrument during external calibration provides traceability for the verification procedure Absolute accuracy is ensured by compensating for any error measured in the internal references Note Self calibrate the digitizer before you perform verification NI SCOPE includes self calibration example programs for LabVIEW CVI and Microsoft Visual...

Page 6: ... NI SCOPE Scope Soft Front Panel 3 Select the device you want to calibrate using the Device Configuration dialog box Edit Device Configuration 4 Launch the Calibration dialog box Utility Self Calibration 5 Click OK to begin self calibration NI SCOPE To self calibrate the NI 5122 5124 programmatically using NI SCOPE complete the following steps 1 Disconnect or disable any AC inputs to the digitizer...

Page 7: ...on rather than an external calibration session the new calibration constants are immediately stored in the EEPROM Therefore you can include this procedure in any application that uses the digitizer 4 Call niScope_close niScope Close VI to close the session handle Set the following parameter vi The instrument handle you obtained from niScope_init ...

Page 8: ...ermined during verification fall within the calibration test limits the device is guaranteed to meet or exceed its published specifications for a full calibration interval two years For this reason you must verify against the calibration test limits when performing verification after adjustment If all of the measurement errors determined during verification fall within the published specifications...

Page 9: ...he complete calibration procedure you verify that the measurement error falls within the calibration test limits Figure 1 shows the programming flow for complete calibration Figure 1 Complete Calibration Programming Flow Adjust Cal Dates and Temperatures Updated Document Post Adjustment Results Document Pre Adjustment Results Calibration Verification Complete Yes No Self Calibrate Verify Verify Me...

Page 10: ...alibration interval without actually performing an adjustment Refer to the Adjusting the NI 5122 5124 section for more information If all of the measurement errors determined during the first verification fall within the published specifications but not within the calibration test limits adjustment is also optional However you cannot update the calibration date because the device will not necessar...

Page 11: ...Specifications Yes Results Within Published Specs Adjustment Optional Update Calibration Dates and Temperatures Without Adjusting No Adjust Cal Dates and Temperatures Updated Adjust Anyway No Calibration Verification Complete Yes Verify Document Post Adjustment Results Document Pre Adjustment Results Meets Calibration Test Limits Review Verification Adjustment Procedure or Return Device No Yes ...

Page 12: ...ct measurements Keep relative humidity between 10 and 90 non condensing or consult the digitizer hardware documentation for the optimum relative humidity Maintain an ambient temperature of 23 5 C Allow a warm up time of at least 15 minutes after the NI SCOPE driver is loaded Unless manually disabled the NI SCOPE driver automatically loads with the operating system and enables the device The warm u...

Page 13: ...cifications Note Always self calibrate the NI 5122 5124 before beginning a verification procedure This section describes the program you must write to verify either the calibration test limits or the published specifications for the NI 5122 5124 Refer to the External Calibration Options section to determine which limits to use in these procedures All verification procedures described in this secti...

Page 14: ... for Vertical Offset Accuracy and Vertical Gain Accuracy Verification Iteration Input Impedance Max Input Frequency Hz Range NI 5122 NI 5124 1 50 Ω 100 000 000 150 000 000 0 2 2 50 Ω 100 000 000 150 000 000 0 4 3 50 Ω 100 000 000 150 000 000 1 4 50 Ω 100 000 000 150 000 000 2 5 50 Ω 100 000 000 150 000 000 4 6 50 Ω 100 000 000 150 000 000 10 7 50 Ω 35 000 000 60 000 000 0 2 8 50 Ω 35 000 000 60 00...

Page 15: ... 10 25 1 MΩ 100 000 000 150 000 000 20 26 1 MΩ 35 000 000 60 000 000 0 2 27 1 MΩ 35 000 000 60 000 000 0 4 28 1 MΩ 35 000 000 60 000 000 1 29 1 MΩ 35 000 000 60 000 000 2 30 1 MΩ 35 000 000 60 000 000 4 31 1 MΩ 35 000 000 60 000 000 10 32 1 MΩ 35 000 000 60 000 000 20 33 1 MΩ 20 000 000 20 000 000 0 2 34 1 MΩ 20 000 000 20 000 000 0 4 35 1 MΩ 20 000 000 20 000 000 1 36 1 MΩ 20 000 000 20 000 000 2...

Page 16: ...iScope Commit VI with the following parameter vi The instrument handle you obtained from niScope_init 5 Short circuit the channel 0 input of the digitizer by connecting the calibrator test head directly to the digitizer and grounding the output of the calibrator 6 Wait 500 ms for the impedance matching of the calibrator to settle 7 Call niScope_InitiateAcquisition niScope Initiate Acquisition VI w...

Page 17: ...Limits and Published Specifications Range NI PXI 5122 NI PCI 5122 Calibration Test Limits V Published Specifications V Calibration Test Limits V Published Specifications V 0 2 0 00057 0 001 0 00114 0 002 0 4 0 00057 0 001 0 00114 0 002 1 0 00057 0 001 0 00114 0 002 2 0 00057 0 001 0 00114 0 002 4 0 0033 0 008 0 0033 0 008 10 0 0033 0 008 0 0033 0 008 20 0 0039 0 01 0 0039 0 01 Table 5 NI 5124 Vert...

Page 18: ...tion 1 0 enabled NISCOPE_VAL_TRUE 3 Call niScope_ConfigureHorizontalTiming niScope Configure Horizontal Timing VI with the following parameters minSampleRate 10 000 000 minNumPts 100 000 refPosition 50 0 numRecords 1 enforceRealtime NISCOPE_VAL_TRUE 4 Call niScope_Commit niScope Commit VI with the following parameter vi The instrument handle you obtained from niScope_init 5 Connect the calibrator ...

Page 19: ...gain as a percentage of input using the formula error a b c d 1 100 where a is the measured positive voltage b is the measured negative voltage c is the applied positive voltage and d is the applied negative voltage Compare the resulting percent error to the Calibration Test Limits or the Published Specifications listed in Table 6 NI 5122 or Table 7 NI 5124 If the result is within the selected tes...

Page 20: ...e Chan Characteristics VI with the following parameters channelList 0 inputImpedance NISCOPE_VAL_50_OHM maxInputFrequency 100 000 000 for NI 5122 150 000 for NI 5124 2 Call niScope_ConfigureVertical niScope Configure Vertical VI with the following parameters channelList 0 range 2 0 offset 0 75 coupling NISCOPE_VAL_DC probeAttenuation 1 0 enabled NISCOPE_VAL_TRUE Table 7 NI 5124 Vertical Gain Stimu...

Page 21: ...Scope Initiate Acquisition VI with the following parameter vi The instrument handle you obtained from niScope_init 8 Call niScope_FetchMeasurement niScope Fetch Measurement VI with the following parameters channelList 0 timeout 1 0 scalarMeasFunction NISCOPE_VAL_VOLTAGE_AVERAGE 9 Output 0 75 V with the calibrator 10 Call niScope_ConfigureVertical niScope Configure Vertical VI with the following pa...

Page 22: ... portion of the verification 16 Move the calibrator test head to the digitizer input channel 1 and repeat steps 1 through 15 replacing 0 with 1 for the channelList parameter You have finished verifying the programmable vertical offset accuracy of the NI 5122 5124 Timing Accuracy Complete the following steps to verify the timing accuracy for the NI 5122 5124 1 Call niScope_ConfigureChanCharacterist...

Page 23: ...itude and 50 Ω load impedance 6 Wait 750 ms for the impedance matching and frequency of the calibrator to settle 7 Call niScope_InitiateAcquisition niScope Initiate Acquisition VI with the following parameter vi The instrument handle you obtained from niScope_init 8 Call niScope_FetchMeasurement niScope Fetch Measurement VI with the following parameters channelList 0 timeout 1 0 scalarMeasFunction...

Page 24: ...Input Frequency for the current iteration in Table 10 NI 5122 or Table 11 NI 5124 2 Call niScope_ConfigureVertical niScope Configure Vertical VI with the following parameters channelList 0 range The Range value for the current iteration in Table 10 NI 5122 or Table 11 NI 5124 offset 0 0 coupling NISCOPE_VAL_DC probeAttenuation 1 0 enabled NISCOPE_VAL_TRUE 3 Call niScope_ConfigureHorizontalTiming n...

Page 25: ...e 100 000 000 for NI 5122 200 000 000 for NI 5124 minNumPts 300 000 refPosition 50 0 numRecords 1 enforceRealtime NISCOPE_VAL_TRUE 10 Call niScope_Commit niScope Commit VI with the following parameter vi The instrument handle you obtained from niScope_init 11 Wait 500 ms for the output of the calibrator to settle 12 Repeat steps 12a through 12d for each Input Frequency listed for the current itera...

Page 26: ...RMS voltage in step 12c and b is the measured RMS voltage in step 8 If the result is within the test limits from Table 10 NI 5122 or Table 11 NI 5124 the device has passed this portion of the verification Move the calibrator test head to the digitizer input channel 1 and repeat steps 1 through 12 replacing 0 with 1 for the channelList parameter ...

Page 27: ... 0 77 1 1 84 400 000 3 3 3 at 80 MHz 3 at 80 MHz 2 100 MHz 50 Ω 0 4 20 100 000 0 27 0 27 0 4 0 4 50 100 000 0 77 0 77 1 1 103 700 000 3 3 3 at 100 MHz 3 at 100 MHz 3 100 MHz 1 MΩ 0 2 20 100 000 0 27 0 27 0 4 0 4 40 100 000 0 77 0 77 1 1 84 400 000 3 3 3 at 80 MHz 3 at 80 MHz 4 100 MHz 1 MΩ 0 4 20 100 000 0 27 0 27 0 4 0 4 50 100 000 0 77 0 77 1 1 103 700 000 3 3 3 at 100 MHz 3 at 100 MHz 5 35 MHz ...

Page 28: ...40 100 000 0 83 0 83 1 5 1 5 96 000 000 3 3 N A 3 at 85 MHz 2 150 MHz 50 Ω 0 4 20 100 000 0 33 0 33 0 5 0 5 50 100 000 0 83 0 83 1 1 100 100 000 1 53 1 53 1 7 1 7 161 800 000 3 3 N A 3 at 150 MHz 3 150 MHz 1 MΩ 0 2 20 100 000 0 42 0 42 0 6 0 6 40 100 000 1 3 1 3 1 5 1 5 89 100 000 3 3 N A 3 at 75 MHz 4 150 MHz 1 MΩ 0 4 20 100 000 0 33 0 33 0 5 0 5 50 100 000 0 83 0 83 1 1 100 100 000 1 53 1 53 1 7...

Page 29: ...tical VI with the following parameters channelList 0 range 0 2 offset 0 0 coupling NISCOPE_VAL_DC probeAttenuation 1 0 enabled NISCOPE_VAL_TRUE 3 Call niScope_ConfigureHorizontalTiming niScope Configure Horizontal Timing VI with the following parameters minSampleRate 100 000 000 minNumPts 1 000 refPosition 50 0 numRecords 50 enforceRealtime NISCOPE_VAL_TRUE 4 Call niScope_ConfigureTriggerEdge with...

Page 30: ... digitizer does time out you must call niScope_Abort niScope Abort VI to end the acquisition 10 To verify the trigger sensitivity on channel 1 repeat steps 1 through 9 using the values from Table 12 iterations 5 through 8 Also change channelList to 1 in steps 1 2 and 9 and connect the calibrator test head to channel 1 in step 6 11 To verify the trigger sensitivity on the external trigger channel r...

Page 31: ...pk 100 MHz sine wave with 50 Ω load impedance 19 0 mVpk pk 150 MHz sine wave with 50 Ω load impedance 4 0 1 25 mV NISCOPE_VAL_ NEGATIVE 5 1 1 25 mV NISCOPE_VAL_ POSITIVE 4 84 mVpk pk 50 MHz sine wave with 50 Ω load impedance 4 84 mVpk pk 50 MHz sinewave with 50 Ω load impedance 6 1 1 25 mV NISCOPE_VAL_ NEGATIVE 7 1 1 25 mV NISCOPE_VAL_ POSITIVE 9 7 mVpk pk 100 MHz sine wave with 50 Ω load impedanc...

Page 32: ... channel 1 input of the digitizer c Configure the calibrator to output an exact 4 V DC signal into a 1 MΩ load impedance If you are using a calibrator other than a Fluke9500B Wavetek 9500 a Connect a 10 MHz 1 Vpp sine or square wave source to channel 0 b Connect the oscilloscope calibrator DC source to channel 1 c Configure the calibrator to output an exact 4 V DC signal into a 1 MΩ load impedance...

Page 33: ...adjust each channel individually However you should repeat the entire verification procedure to verify a successful adjustment Calibration Utilities NI SCOPE supports several calibration utilities that allow you to retrieve information about adjustments performed on the NI 5122 5124 change the external calibration password and store small amounts of information in the onboard EEPROM You can retrie...

Page 34: ...he National Instruments Web site is your complete resource for technical support At ni com support you have access to everything from troubleshooting and application development self help resources to email and phone assistance from NI Application Engineers A Declaration of Conformity DoC is our claim of compliance with the Council of the European Communities using the manufacturer s declaration o...

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