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Unformatted text preview: Derived units
square meter
cubic meter
hertz
kilogram per cubic meter
meter per second
radian per second
meter per second squared
radian per second squared
neWIon
newton per sq meter
sq meter per second
newtonsecond per sq meter
jouie
watt
coulomb
volt ‘ . volt per meter
ohm farad Weber
’ hemy ' tesla
‘ ampere per meter
ampere lumen candeia per sq meter
lux N's/m (5") (kg/ms) (N/m)
(J/s)
(A/s)
(W/A) (V/A)
(A/s/V)
(V/S)
(V/s/A)
(Wb/mi) (Cd/5r) (lm/m3) mu...” .., INSPECTION euro TEST 18.l Damascus of Fundamental Units of the SI System
Deﬁnition 650 7” 7‘ 1'“ i {:e “A w.lf pa. :3 Wavelengthiin vacuo ol' the unperturbed
tranSttton lam—ads tn ' Kr
/Mass ol’the international kilogramac Sevres France
[/3! 556 925 974 7 ot‘the tropical year at l2h ET. 0 January
5" e g 0 “£1 / £900. supplementarily deﬁned in [964 in terms of {he cesium F_ 4: M. O to F. 3: M. 0. transition, the Frequency assigned
being 9 I93 63l 770 Hz I , l , /. Defined in the thermodynamic seal:
‘ e” V ' " triple point onater (freezin:
The constant cun'ent which: if maintained in two straight parallel
conductors of inﬁnite length, of negligible circular sections.
and placed 1 m apart in a vacuum. will produce between these
conductors a force equal to 2 X l0" mks unit of Force per
meter of length.
L; (“wk a} (at ”1/60 of the intensity 'ot‘l cm2 ol‘a perfect radiator at the
temperature of freezing platinum.
H a i a. I, An amount ofsubszance whose weight in grams numerically
equals the molecular formula weight. \\ l<{105v—k""' e by assigning 373.l6 K to the
g point. 37315 K = 0°C)
Amp: v‘i / QUALITY CONTROL HANDBOOK PRIMARY
R EFERENCE
STANDARDS TRANSFER STANDARDS
PuL L4. ‘b‘ WORKING
STANDARDS GAGES, INSTRUMENTS
AND EQUIPMENT USED
TO MEASURE PROCESS AND
PRODUCT CHARACTERISTICS FIG. 18A Hierarchy of standards. MST" 9‘0 mew 0“ Fame
gtdo #— B. Measurement Terms
and Deﬁnitions C. Gage Capability Chapter 9 Measurement System and Gage Capability Accuracy is the deviation of the measured or ob
served value from the true value. Precision of a measurement is related to its re
peatability in terms of the deviation of a group of
observations from a mean value. While the terms accuracy and precision are often
used interchangeably, they could be distinguished
as accuracy being the measure of the approach to a
true value, while precision is a measure of consist
ency or repeatability. (See Harris in Background
References.) Repeatability is often used to describe measure
ment variation obtained when one person meas—
ures the same dimension or characteristic several
times with the same gage or test equipment (some?
times referredto as "equipment variation"). Reproducibility is a term popularized in the auto
motive industry as representing the variation in
measurement averages when more than one per—
son measures the same dimension or characteristic
using the same measuring instrument. Stability refers to the variation inthe measure»
ment averages when the measuring instrument
values are recorded over a Speciﬁed time interval. Other terms used to describe certain properties of
gages include: sensitivity, resolution, calibration
accuracy and ampliﬁeaeion, and others. See
sources such as Farago twisted in the background
references for additional explanations of'terms. When referring to gage capability. we are getter
ally looking at the accuracy, repeatability, reproa
ducibility and stability combined into a single
value. These capability elements have been depicted
graphically by Charbonneau and Webster. (See
Background References). At the left is shown the repeatability or the ex
pected variation in one person's readings The_av
gages fig three different people are shown as XA,
X“, and Xr, and the reproducibility distribution
represents the average variation. Accuracy would be calculated by averaging 33“, in, 32c, and taking
the difference between [this ﬁgure and the true
value. Stability appears as a distribution in the
second time period and again is represented as a
variation in average values. The capability is de—
picted as the diaﬁference between the extremes en
countered over the‘time period. Chapter 9 D. Gage Capability
Studies (cont’d) 2. Formal Gage Study A more comprehensive gage study can identify
the proportion of variation contributed by both the
gage repeatability and reproductibility, commonly
referred to as a gage R & R study. For example, poor reproducibility would indicate
a need for operator training in use ofthe gage or a
requirement for better readability A lack of re—
peatability would suggest the need for gage main
tenance, gage redesign or selection ofanother
type of measuring device. Thisrcomplete gage study couldbe performed
with several different operators‘tinspecwrs or
testers) each performing several different mea—
surement trials. To illustrate, we can use a form similar to that
presented by Charhonneau and Webster for up to
three trials for each of three different operators,
The average range (R) is used to estimate the
equipment variation (repeatability), and the ap—
praiser variation (reproducibility) is derived from
the differences in averages (inn). Measurement System and Gage Capability For both repeatability and ceproducibility, varia—
tion is based on 2575 standard deviations (99% t
the normal distribution). The combined variabil
ity is determiaed by adding the variance of both
and the R & R is determined. Using this. method, the generayll y recognized critt
ria for gage acceptability aod‘capability (R & R
divided by the speciﬁcation tolerance) is: ' Under l0%: acceptable gage  I0% to 30%: may be acceptable ' Over 30%; gauge is anncceplable and should
‘ be correctedror'replaced Chuplcr 9 Measurement System andGage Capability Variable Gage Study
(Shun Method) Inspeclur A InSpectoar 8 Range (A ~13) Sum M Ranges: (All numbers in lcnlhs ohm inch). " ‘ .7,
1 Average Range (ﬂ) 3 g = ___i._ = 4L
: Gage Emu : 4.33 ('ﬁ) = 4'53 [‘4 1 #
Gage Errur I H 41/ 7 [572.5/9}.
Speciﬁcmiun 'l‘ulcruncc 40 . H
> l 40 [42 Chapter 9 ‘ Measurement System and Gage Capability Measurement System/Gage Capability
Calculation Worksheet ' PallIASm‘ Name Jhdff Gage Name Mtcrnmt far
_em Madam "emmm
SpedficaIiou .375 5 . I202. Gage type / [he/'1 Zevo Equals , J7 g); Parmo 1’15 5’56 Operalm A B C
SamplaNo (s1 Tiial 2nd Ttial 3rd Tn'al Range Isl Trial 2011 Trial and Ttial ' Range 15! Thal 2nd Tvial 3rd Trial I Ranga
' JL I5 57 .z A 57 5? 56 2 5e, 57 5:, l
2 L3 5.2 4,2 / a, 1/ £4! 6 ’r’ 0 a 1—] 44,! 4 1/ ,1
3 £6 54 55 9.2 57 55 5c, :2 15 5; 55 a
4 .57 65 5L ,2. 5c .57 I5 01 5‘ .57 55 .2
5 5) .53. .57 I 59 (,0 Lo 1 57 an 60. 3
6 54 55 52.1 .2 40 .57 J7 J .55 .57 5s; ,2
7 a 5; 54 / 5! 5: 5!: z if 55 57 ,2
a .57 67 66 / 57 5f 57 I ‘57 527 J7 ' r
_9 7 50’ 5.5 54 / 7 £4 if 7 4,5 7_/_ 5‘?” 5+! 45 /
"J 55’ _ .57 £7 / 5/ pa £0 / 5.? 57 40 7 0L
'I'olals 5X2 673 571/ I51 5931 59/ if; Af 5 74 5);; 535' /g
n. m! i a“ 43’ 7— a  M:
N—v—x
Sum I71 9 Sum / 7 70 Sum /7.;/_7
R. 57.45 I 2.. L590 if éxgg
3:33:33me {Lﬁ J‘ﬁfux , £5 , _37 Y7 #
Meteﬁisumeaverageolﬁ. . E . ﬁt /.4 __‘ / 5 + 1.; V ._. 4/75 ,7 [:2
D. , 327lol2lrialsov25316r3tfials ' 3 ll any individual range exceeds this Hunt. the measwemerdl 0: reading should be reviewed.
repealed. corrected Mdiscarded as appropnale. and new averages and ranges should be computed, Measurement SyslemIGage Capabitil y Analysis : Equipment Variation ("Repealabﬂily") , Kﬁ — J‘05 x A a I 4 5‘? 'Flepoalauihly
when: K. " 456lov2llialSOrBﬂSlotSlriais. ,2 7 / 3 7 .....7~» ‘0 . 7
OperalorVanaliaM Reproduclblllly l 7 K,X.... , ﬂ 1: —__ — Repmducihility
where: K, : 3.65lor20peralors or 2770 loraoperalors.
i... is Ihe dlﬂerence between lhe max; and min; To1al"ﬁepealabilily" and “Hepwducibillly” Variation (RaRI r V lFlepeatabililyF + (Reproducmiliwr Gage Capahmly :Wllff l"( 3.7 )2=\/Jo,91 + [35? =Jiél: 59
Gage ﬂammability Delermlnallun: . rcialeageCauaWY‘F‘Lm : ﬂag5'7 = W
m .004 ~'——
Nulas i
Analysts perimmed by: Dale ...
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 Spring '11
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