Author:Gary Bennett – National Instruments Metrology Laboratory Manager
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NCSLI 2013 Conference 1 How to Achieve a 0.01 µV/V Deviation on Your 10 Vdc Proficiency Test Without using a Josephson Array Author: Gary Bennett – National Instruments Metrology Laboratory Manager Speaker: Jorge Martins – National Instruments Principal Metrology Engineer
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How to Achieve a 0.01 µV/V Deviation on Your 10 Vdc Proficiency Test Without using a Josephson Array. Author:Gary Bennett – National Instruments Metrology Laboratory Manager Speaker: Jorge Martins – National Instruments Principal Metrology Engineer. Learning Objectives. - PowerPoint PPT Presentation
Transcript of Author:Gary Bennett – National Instruments Metrology Laboratory Manager
NCSLI 2013 Conference1
How to Achieve a 0.01 µV/V Deviation on Your 10 Vdc Proficiency Test
Without using a Josephson Array
Author: Gary Bennett – National InstrumentsMetrology Laboratory Manager
Speaker: Jorge Martins – National InstrumentsPrincipal Metrology Engineer
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Learning Objectives
• Activities required to maintain a 10 Vdc reference standard
• Tools available to make precision 10 Vdc transfer measurements
• Overview of techniques to track measured values and project future values of precision standards
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Opportunity for Internal Support
Need to perform artifact calibrations on Fluke 5720A to maintain the 90 day specifications
• Purchased:– 4x 10 Vdc Reference Standards– Data Proof VoltRef SW and 160B scanner– Nanovoltmeter
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Requirements
30 Days 90 Days 1 Year10 V 0.3 0.8 2.0
Stability (± µV/V)Output Voltage
10 Vdc uncertainty for calibrator adjustment is:±1.5 µV/V
10 Vdc Reference Stability Specification
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Options• Expand the 90 day specification of the 57x0 as
per mfg. manual
• Shorten interval of 10 Vdc Zener references
• Buy a 10 Vdc with history … that you can trust!
• Devise a process to expedite the characterization of our Zener References
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Our Chosen Method
• Calibrate all 4 using MAP program after six months.– Measure the travelling standard
• Create procedure to measure the travelling standard• Review the previous 6 months of VoltRef data• Determine uncertainty
– Measure all our 10 Vdc references against the travelling standard using the MAP provider’s procedure
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Measurements Prior to 2nd Calibration
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Result of 1st Proficiency Test
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What Happened?
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2nd Calibration
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2nd Calibration Results
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3rd Calibration 2nd Proficiency Test
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3rd Calibration, 2nd Proficiency Test
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Proficiency Test #2
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Projected Values and 3rd Calibration
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3rd Calibration
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Proficiency Test #3
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4th Calibration
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Proficiency Test #4
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5th Calibration
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5th Calibration Cell #1
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Uncertainty Components
• Calibration Uncertainty (Travelling standard)• Atmospheric Pressure• Temperature• Noise• Type A Statistical • Uncertainty of Projected Value• Hysteresis Error
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Conclusion• VoltRef works very well with the proper drift
information for each cell• Tools are available to make the data gathering
less painful• Understanding the normal differences in
performance of individual references is important• Gathering history on reference standards is
expensive
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Questions
