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 National Instruments Corporation

7

NI 5922 Calibration Procedure

specifications, you must perform an adjustment to restore the device 
operation to its published specifications.

The 

Complete Calibration

 section describes the recommended calibration 

procedure. The 

Optional Calibration

 section describes alternative 

procedures that allow you to skip adjustment if the device already meets its 
calibration test limits or published specifications.

Complete Calibration

Performing a complete calibration is the recommended way to guarantee 
that the NI 5922 meets or exceeds its published specifications for a 
two-year calibration interval. At the end of the 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

Meets

Calibration

Test Limits?

Review Verification/

Adjustment Procedure

or Return Device

Содержание NI 5922

Страница 1: ...on 2 Calibration Intervals 2 Software and Documentation 2 Self Calibration Procedures 4 MAX 5 Scope SFP 5 NI SCOPE 5 External Calibration Options 6 Complete Calibration 7 Optional Calibration 8 Extern...

Страница 2: ...constants in the EEPROM and is equivalent to a factory calibration at NI Because the external calibration procedure changes all EEPROM constants it invalidates the original calibration certificate If...

Страница 3: ...nding LabVIEW VI in parentheses The C function calls are valid for any compiler capable of calling a 32 bit DLL Many of the functions use constants defined in the niScopeCal h file To use these consta...

Страница 4: ...ing 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 Microsof...

Страница 5: ...om the Scope SFP complete the following steps 1 Disconnect or disable any AC inputs to the digitizer 2 Launch the Scope SFP by selecting Start Programs National Instruments NI SCOPE Scope Soft Front P...

Страница 6: ...on can be used to ensure that the adjustment process was successful or to determine if the adjustment process must be performed During verification you must compare the measurement error to limits giv...

Страница 7: ...orming a complete calibration is the recommended way to guarantee that the NI 5922 meets or exceeds its published specifications for a two year calibration interval At the end of the complete calibrat...

Страница 8: ...ion date effectively resetting the calibration interval without actually performing an adjustment Refer to the Adjusting the NI 5922 section for more information If all of the measurement errors deter...

Страница 9: ...mits Yes No Meets Published Specifications Yes Results Within Published Specs Adjustment Optional Update Calibration Dates and Temperatures Without Adjusting No Adjust Cal Dates and Temperatures Updat...

Страница 10: ...brator to the input BNC of the digitizer or use a short 50 BNC coaxial cable if necessary Long cables and wires act as antennae picking up extra noise that can affect measurements Keep relative humidi...

Страница 11: ...ion procedure may not be required Refer to the External Calibration Options section for more information The external calibration procedure automatically stores the calibration date to allow traceabil...

Страница 12: ...ConfigureVertical niScope Configure Vertical VI with the following parameters channelList 0 range The Range value for the current iteration from Table 3 offset 0 0 coupling NISCOPE_VAL_DC probeAttenua...

Страница 13: ...the BNC inputs of the NI 5922 No input signal is needed because the NI 5922 internal 50 resistor connects the input to ground 2 Call niScope_ConfigureChanCharacteristics niScope Configure Chan Charac...

Страница 14: ...ned from Table 4 a Add up the squares of each element in the returned array starting with element i and ending with element 26 215 The first element in the array is element 0 b Take the square root of...

Страница 15: ...cal niScope Configure Vertical VI with the following parameters channelList 0 range 2 offset 0 0 coupling NISCOPE_VAL_DC probeAttenuation 1 0 enabled NISCOPE_VAL_TRUE 4 Call niScope_ConfigureHorizonta...

Страница 16: ...maxInputFrequency 0 8 Call niScope_InitiateAcquisition niScope Initiate Acquisition VI with the following parameter vi The instrument handle you obtained from niScope_init 9 Call niScope_FetchMeasure...

Страница 17: ...the following parameters channelList 0 range The Range value for the current iteration from Table 6 offset 0 0 coupling NISCOPE_VAL_DC probeAttenuation 1 0 enabled NISCOPE_VAL_TRUE 3 Call niScope_Con...

Страница 18: ...etchMeasurement niScope Fetch Measurement VI with the following parameters channelList 0 timeout 1 0 scalarMeasFunction NISCOPE_VAL_VOLTAGE_AVERAGE 13 Calculate the error in the vertical gain as a per...

Страница 19: ...ical niScope Configure Vertical VI with the following parameters channelList 0 range 10 offset 0 0 coupling NISCOPE_VAL_DC probeAttenuation 1 0 enabled NISCOPE_VAL_TRUE 3 Call niScope_ConfigureHorizon...

Страница 20: ...nction NISCOPE_VAL_FFT_FREQUENCY 9 Calculate the error in timing as parts per million ppm using the following formula where a the measured frequency Compare the result to the Calibration Test Limits o...

Страница 21: ...ltime NISCOPE_VAL_TRUE 4 Call niScope_ConfigureTriggerEdge niScope Configure Trigger Edge VI with the following parameters triggerSource 0 level 0 1 slope NISCOPE_VAL_POSITIVE triggerCoupling NISCOPE_...

Страница 22: ...ements within array X2 so that index 0 of the array contains the element with the largest value Denote the result as X3 A circular rotation takes the first element of the array makes it the last eleme...

Страница 23: ...listed in the Calibration Test Limits column or the Published Specifications column in Table 8 If the result is less than the selected test limit the device has passed this portion of the verification...

Страница 24: ...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 1...

Страница 25: ...ized data from the input channel ADC when performing an analog trigger on CH 0 or CH 1 Verifying the trigger sensitivity for the input channels is not necessary Adjusting the NI 5922 If the NI 5922 su...

Страница 26: ...SelfCalibrate niScope Cal Self Calibrate VI with the following parameters channelList VI_NULL option VI_NULL 6 Call niScope_CalAdjustVCXO niScope Cal Adjust VCXO VI with the following parameter stimul...

Страница 27: ...you can retrieve all the data programmatically using NI SCOPE functions MAX To retrieve data using MAX complete the following steps 1 Select the device from which you want to retrieve information from...

Страница 28: ...ct supports calibration you can obtain the calibration certificate for your product at ni com calibration National Instruments corporate headquarters is located at 11500 North Mopac Expressway Austin...

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