NSWC Corona Division Presentation Format

WARFARE CENTERS
CORONA
Navy METCAL Technical Agent
Position on Traceability
Mr. Robert E. Fritzsche
NSWC Corona
[email protected]
951.273.5518
17 July 2013
DISTRIBUTION STATEMENT F. Further dissemination only as directed by Naval Surface Warfare Center, Corona Division Commanding Officer. (UNCLASSIFIED)
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WARFARE CENTERS
CORONA
Navy METCAL Program Scope
Test Equipment
Different Models:
Different S/N:
~ 140K
~ 1,850K
Calibration Standards
Different Models:
~ 5K
Different S/N:
~ 225K
~ 1.85M
~225K
Approved Calibration Procedures
Annual Engineering
Inquiries/Actions
Annual Calibrations
~800K
Calibration Laboratories
Shore 165
Ship 244
~5,000
~2,000
409
We have a lot of stuff !
DISTRIBUTION STATEMENT F. Further dissemination only as directed by Naval Surface Warfare Center, Corona Division Commanding Officer. (UNCLASSIFIED)
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WARFARE CENTERS
CORONA
Navy Definitions
Calibration: The comparison of a measurement system or device of
unverified accuracy to a measurement system or device of known and
greater accuracy to detect any variation from required performance
specifications of the unverified measurement system or device.
Traceability: The process by which the assigned value of a
measurement is compared directly or indirectly through a series of
calibrations to the value assigned to the U.S. national standard or to
natural physical constants.
Test Accuracy Ratio (TAR)/Test Uncertainty Ratio (TUR): The
ratio of the test instrument uncertainty to the uncertainty of the
calibration standard or calibration system. (Note that the terms TAR and TUR are
used interchangeably in the Navy).
DISTRIBUTION STATEMENT F. Further dissemination only as directed by Naval Surface Warfare Center, Corona Division Commanding Officer. (UNCLASSIFIED)
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WARFARE CENTERS
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Navy Traceability Philosophy
Measurement requirements will be identified for weapon
and test system parameters.
 Calibration requirements will be based on system
measurement requirements, where known.
 A test accuracy ratio (TAR) of 4:1 or better will be
maintained, where possible, to reduce the risk of
erroneous test decisions (false accept/reject) at each
link in the traceability chain, from weapon system to
National Standards.
 Use of TAR requires knowledge of error components
and mitigation of errors not associated with the
calibration standard(s) in the calibration system.

DISTRIBUTION STATEMENT F. Further dissemination only as directed by Naval Surface Warfare Center, Corona Division Commanding Officer. (UNCLASSIFIED)
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WARFARE CENTERS
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Navy Traceability Example
Fleet
Maintainers
Weapon System
(ex: F/A-18)
4:1 TAR
4:1 TAR
National Institute of
Standards & Technology
Fleet “I” Level
Calibration Labs
Navy Primary
Standards Lab
4:1 TAR
Depot “D” Level
Calibration Labs
4:1 TAR
Ensure individual measurement results can be traced through an
unbroken chain of calibrations to National Standards or references
DISTRIBUTION STATEMENT F. Further dissemination only as directed by Naval Surface Warfare Center, Corona Division Commanding Officer. (UNCLASSIFIED)
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WARFARE CENTERS
CORONA
Navy Traceability Approach
Qualified technicians will perform calibrations using
calibrated measurement standards in accordance with
approved, documented calibration procedures in a
certified calibration laboratory (OPNAVINST 3960.16A,
NAVAIR 17-35TR-1)
 Laboratory environmental requirements will be defined
to ensure, where possible, that environmental impacts
to the measurements will be so small as to be
considered negligible (NAVAIR 17-35FR-06)
 Compliance with laboratory environmental requirements
will be periodically verified by trained assessors
(NAVAIR 17-35QAC-01B)

DISTRIBUTION STATEMENT F. Further dissemination only as directed by Naval Surface Warfare Center, Corona Division Commanding Officer. (UNCLASSIFIED)
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WARFARE CENTERS
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Navy Calibration Lab Support
M Instrument Calibration Procedures
E
T
R
O
L Calibration Standards
O
G
Y
CALIBRATION LABORATORY
Probability of
Wrong Decision
E METCAL Documents
N
G
I
N
•
E Intervals
•
E
R
•
I
0 1:1
4:1
Accuracy Ratio
N
G
To ensure that Navy Calibrators
RISK OF MAKING WRONG DECISIONS
AT
VARIOUS ACCURACY RATIOS
Controlled, Monitored Environment
Documented, Certified Quality System
Trained Calibration Technicians
have the proper tools to do the job
DISTRIBUTION STATEMENT F. Further dissemination only as directed by Naval Surface Warfare Center, Corona Division Commanding Officer. (UNCLASSIFIED)
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WARFARE CENTERS
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
Measurement uncertainty will be controlled (bounded)
rather than specifically calculated, where possible
‒
‒
‒
‒

Navy Traceability - Summary
Reduces the burden on the calibration technicians
Provides for more efficient, less costly calibration
Maintains technical integrity of measurement
Mirrors what is done in Legal Metrology community
Use of TAR is technically valid, but requires the following:
‒
‒
The error contribution of the calibration standard(s) is significantly
greater than other error components
Controls are in place to minimize error contributions due to:
• Environmental conditions (ex: temperature, humidity, vibration, etc.)
• Human error (training; standardized, technically sound processes)
• Other factors, as applicable

Where errors cannot be mitigated, uncertainty must be
calculated and documented
DISTRIBUTION STATEMENT F. Further dissemination only as directed by Naval Surface Warfare Center, Corona Division Commanding Officer. (UNCLASSIFIED)
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