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Code of Federal Regulations Title 7. Agriculture § 7.42.140 Operating Characteristic (OC) curves for on-line sampling and inspection

Current as of October 02, 2022 | Updated by FindLaw Staff

(a) This section contains the Operating Characteristic (OC) curve for each of the sampling plans given in Tables I, I–A, II, II–A, III, and III–A. The OC curve and the corresponding sampling plans are listed by AQL.

(b) Different acceptance and rejection criteria are provided for each AQL. The criteria for each AQL must be obtained from the applicable sampling plan tables.

(c) The curves show the ability of the various sampling plans to distinguish between good and bad lots. This can be illustrated by examining OC curve 6 for an AQL of 0.25 defects per hundred units in the Reduced and Normal Inspection Plans. If the quality of the lots submitted for inspection is poorer than the AQL of 0.25 defects per hundred units, fewer lots will be accepted. For example, OC curve 6 shows that when the quality of lots submitted for inspection is 1.0 defects per hundred units, only 26 percent of the lots are expected to be accepted. Conversely when the quality of the lots submitted for inspection is better than the AQL of 0.25 defects per hundred units, most lots are expected to be accepted. For example, the same OC curve 6 shows that when the quality of lots submitted for inspection is 0.10 defects per hundred units, about 99 percent of the lots are expected to be accepted.

(d) The table of sampling plans that correspond to OC curve 6 can be found over the curves for an AQL of 0.25 defects per hundred units in the Reduced and Normal Inspection Plan. An examination of this table reveals that there is one single and one double sampling plan that have OC curves comparable to OC curve 6. The first plan listed is a single plan requiring the inspection of 500 individual containers. Under this plan the lot is accepted as meeting the requirements for an AQL of 0.25 if there are 3 or less defects in the sample or rejected if there are 4 or more defects in the sample.

(e) The next plan that is listed in the column headed 6 for an AQL of 0.25 is a double sampling plan that requires the initial inspection of 228 individual containers. The lot will be accepted as meeting the requirements of an AQL of 0.25 if there are no defects in the sample, and rejected if there are 3 or more defects in the sample. In the event that the number of defects is between the acceptance (0) and rejection (3) numbers, additional containers must be inspected. In this case, the table indicates that a total of 516 containers must be inspected before a decision can be made to either accept or reject the lot. This will require the inspection of 288 more containers (516—228=288).

If there are 3 or less defects in the total sample, the lot will be accepted. If there are 4 or more defects in the total sample, the lot will be rejected. The other double sampling plans operate in a similar manner with the only differences being the sample sizes and acceptance and rejection numbers.

REDUCED AND NORMAL INSPECTION PLANS—SAMPLING PLANS AND OPERATING CHARACTERISTIC (OC) CURVES FOR AQL = 0.15 DEFECTS PER HUNDRED UNITS

[Sampling plans—AQL = 0.15]

Identification number of OC curve

Comparable sampling

R1

R2

R3

R4

plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single․․․․․․․․․․․․․․․․․․․․․

29

1

2

84

1

2

126

0

1

315

1

2

Double․․․․․․․․․․․․․․․․․․․․․

18

0

2

36

0

2

․․․․․

․․․․․

․․․․․

․․․․․

․․․․․

․․․․․

36

1

2

96

1

2

․․․․․

․․․․․

․․․․․

․․․․․

․․․․․

․․․․․

REDUCED AND NORMAL INSPECTION PLANS—SAMPLING PLANS AND OPERATING CHARACTERISTIC (OC) CURVES FOR AQL = 0.15 DEFECTS PER HUNDRED UNITS

[Sampling plans—AQL = 0.15]

Identification number of OC curve

N4

N5

N6

Comparative sampling plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

168

1

2

264

1

2

500

2

3

Double

120

0

2

174

0

2

252

0

3

180

1

2

336

1

2

540

2

3

Identification number of OC curve

N7

N8

Comparable sampling plans

nc

Ac

Re

nc

Ac

Re

Single․․․․․․․․․․․․․․․․․․․․․․․․․․․

800

3

4

1,250

4

5

Double․․․․․․․․․․․․․․․․․․․․․․․․․․․

456

0

4

․․․․․․․․․․․

․․․․․․․․․․․

․․․․․․․․․․․

864

3

4

․․․․․․․․․․․

․․․․․․․․․․․

․․․․․․․․․․․

nc = Cumulative sample size. Ac = Acceptance number. Re = Rejection number.

TIGHTENED INSPECTION PLANS—SAMPLING PLANS AND OPERATING CHARACTERISTIC (OC) CURVES FOR AQL = 0.15 DEFECTS PER HUNDRED UNITS

[Sampling plans—AQL = 0.15]

Identification number of OC curves

1

2

3

4

Comparable sampling plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

264

0

1

500

1

2

800

2

3

1,250

3

4

Double

360

0

2

456

0

3

 576

0

3

516

1

2

864

2

3

1,296

3

4

nc = Cumulative sample size. Ac = Acceptance number. Re = Rejection number.

REDUCED AND NORMAL INSPECTION PLANS—SAMPLING PLANS AND OPERATING CHARACTERISTIC (OC) CURVES FOR AQL = 0.25 DEFECTS PER HUNDRED UNITS

[Sampling plans—AQL = 0.25]

Identification number OC curves

R1

N2

R3

N and R4

Comparable sampling plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

29

1

2

84

0

1

84

1

2

168

1

2

Double

18

0

2

36

0

2

120

0

2

168

0

18

1

2

96

1

2

180

1

2

348

2

Identification number OC curves

N and R5

N6

N7

Comparable sampling plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

315

2

3

500

3

4

800

4

5

Double

3

228

0

3

3

516

3

4

nc = Cumulative sample size. Ac = Acceptance number. Re = Rejection number.

TIGHTENED INSPECTION PLANS—SAMPLING PLANS AND OPERATION CHARACTERISTICS (OC) CURVES FOR AQL = 0.25 DEFECTS PER HUNDRED UNITS

[Sampling plans—AQL = 0.25]

Identification number of OC curves

Comparable sampling

1

2

3

4

5

plans․․․․․․․․․․․․․․․․․․․

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single․․․․․․․․․․․․․․․․․․

168

0

1

315

1

2

500

2

3

800

3

4

1,250

4

5

Double․․․․․․․․․․․․․․․․․․

․․․․․

․․․․․

․․․․․

168

0

2

228

0

3

456

0

4

․․․․․

․․․․․

․․․․․

․․․․․

․․․․․

․․․․․

348

1

2

516

2

3

864

3

4

․․․․․

․․․․․

․․․․․

nc = Cumulative sample size. Ac = Acceptance number. Re = Rejection number.

REDUCED AND NORMAL INSPECTION PLANS—SAMPLING PLANS AND OPERATING CHARACTERISTIC (OC) CURVES FOR AQL = 0.50 DEFECTS PER HUNDRED UNITS

[Sampling plans—AQL = 0.50]

Identification number of OC curves

R1

N and R2

N and R3

Comparable sampling plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

29

1

2

84

1

2

168

2

3

Double

18

0

2

36

0

2

120

0

3

36

1

2

96

1

2

180

2

3

Identification number of OC curves

N and R4

N5

N6

Comparable sampling plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

315

3

4

500

5

6

800

7

8

Double

168

0

4

228

0

5

348

3

4

516

5

6

nc = Cumulative sample size. Ac = Acceptance number. Re = Rejection number.

TIGHTENED INSPECTION PLANS—SAMPLING PLANS AND OPERATING CHARACTERISTIC (OC) CURVES FOR AQL = 0.50 DEFECTS PER HUNDRED UNITS

[Sampling plans—AQL = 0.50]

Identification number of OC curves

1

2

3

Comparable sampling plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

168

1

2

315

2

3

500

3

4

Double

120

0

2

168

0

3

228

0

3

180

1

2

348

2

3

516

3

4

Identification number of OC curves

4

5

Comparable sampling plans

nc

Ac

Re

nc

Ac

Re

Single․․․․․․․․․․․․․․․․․․․․․․․․․․․

800

4

5

1,250

6

7

Double․․․․․․․․․․․․․․․․․․․․․․․․․․․

456

1

5

․․․․․․․․․․․

․․․․․․․․․․․

․․․․․․․․․․․

864

4

5

․․․․․․․․․․․

․․․․․․․․․․․

․․․․․․․․․․․

nc = Cumulative sample size. Ac = Acceptance number. Re = Rejection number.

REDUCED AND NORMAL INSPECTION PLANS—SAMPLING PLANS AND OPERATING CHARACTERISTIC (OC) CURVES FOR AQL = 1.00 DEFECTS PER HUNDRED UNITS

[Sampling plans—AQL = 1.00]

Identification number of OC curves

Comparable sampling

R1

N and R2

N and R3

plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

29

1

2

84

2

3

168

4

5

Double

18

0

2

36

0

3

120

2

5

36

1

2

96

2

3

180

4

5

Identification number of OC curves

Comparable sampling

N and R4

N5

N6

plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

315

6

7

500

9

10

800

13

14

Double

168

1

5

228

2

7

348

7

8

516

9

10

nc = Cumulative sample size. Ac = Acceptance number. Re = Rejection number.

TIGHTENED INSPECTION PLANS—SAMPLING PLANS AND OPERATING CHARACTERISTIC (OC) CURVES FOR AQL = 1.00 DEFECTS PER HUNDRED UNITS

[Sampling plans—AQL = 1.00]

Identification number of OC curves

Comparable sampling

1

2

3

plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

168

2

3

315

3

4

500

5

6

Double

120

0

3

168

0

4

228

0

5

180

2

3

348

3

4

516

5

6

Identification number of OC curves

Comparable sampling

4

5

plans

nc

Ac

Re

nc

Ac

Re

Single

800

7

8

1,250

10

11

Double

456

2

6

864

8

9

nc = Cumulative sample size. Ac = Acceptance number. Re = Rejection number.

REDUCED AND NORMAL INSPECTION PLANS—SAMPLING PLANS AND OPERATING CHARACTERISTIC (OC) CURVES FOR AQL = 1.50 DEFECTS PER HUNDRED UNITS

[Sampling plans—AQL = 1.50]

Identification number of OC curves

Comparable sampling

R1

N and R2

N and R3

plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

29

1

2

84

3

4

168

5

6

Double

18

0

2

36

0

4

120

2

6

36

1

2

96

3

4

180

5

6

Identification number of OC curves

Comparable sampling

N and R4

N5

N6

plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

315

8

9

500

12

13

800

18

19

Double

168

2

7

228

3

9

348

9

10

516

12

13

nc = Cumulative sample size. Ac = Acceptance number. Re = Rejection number.

TIGHTENED INSPECTION PLANS—SAMPLING PLANS AND OPERATING CHARACTERISTIC (OC) CURVES FOR AQL = 1.50 DEFECTS PER HUNDRED UNITS

[Sampling plans—AQL = 1.50]

Identification number of OC curves

Comparable sampling

1

2

3

plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

168

4

5

315

6

7

500

9

10

Double

120

2

5

168

1

5

228

2

7

180

4

5

348

7

8

516

9

10

Identification number of OC curves

Comparable sampling

4

5

plans

nc

Ac

Re

nc

Ac

Re

Single

800

13

14

1,250

19

20

Double

456

5

10

864

14

15

nc = Cumulative sample size. Ac = Acceptance number. Re = Rejection number.

REDUCED AND NORMAL INSPECTION PLANS—SAMPLING PLANS AND OPERATING CHARACTERISTIC (OC) CURVES FOR AQL = 2.50 DEFECTS PER HUNDRED UNITS

[Sampling plans—AQL = 2.50]

Identification number of OC curves

Comparable sampling

R1

N and R2

N and R3

plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

29

2

3

84

4

5

168

7

8

Double

18

0

3

36

0

4

120

3

7

36

2

3

96

4

5

180

8

9

Identification number of OC Curves

Comparable sampling

N and R4

N5

N6

plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

315

13

14

500

18

19

800

27

28

Double

168

5

10

228

5

11

348

14

15

516

19

20

nc = Cumulative sample size. Ac = Acceptance number. Re = Rejection number.

TIGHTENED INSPECTION PLANS—SAMPLING PLANS AND OPERATING CHARACTERISTIC (OC) CURVES FOR AQL = 2.50 DEFECTS PER HUNDRED UNITS

[Sampling plans—AQL = 2.50]

Identification number of OC curves

Comparable sampling

1

2

3

plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single․․․․․․․․․․․․․․․․․․

168

5

6

315

8

9

500

12

13

Double․․․․․․․․․․․․․․․․․․

120

2

6

168

2

7

228

3

9

180

5

6

348

9

10

516

12

13

Identification number of OC curve

Comparable sampling

4

5

plans

nc

Ac

Re

nc

Ac

Re

Single․․․․․․․․․․․․․․․․․․․․․․․․․․․

800

18

19

1,250

26

27

Double․․․․․․․․․․․․․․․․․․․․․․․․․․․

456

8

13

․․․․․․․․․․․

․․․․․․․․․․․

․․․․․․․․․․․

864

19

20

․․․․․․․․․․․

․․․․․․․․․․․

․․․․․․․․․․․

nc = Cumulative sample size. Ac = Acceptance number. Re = Rejection number.

REDUCED AND NORMAL INSPECTION PLANS—SAMPLING PLANS AND OPERATING CHARACTERISTIC (OC) CURVES FOR AQL = 4.00 DEFECTS PER HUNDRED UNITS

[Sampling plans—AQL = 4.00]

Identification number of OC curves

Comparable sampling

R1

N and R2

N and R3

plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

29

3

4

84

6

7

168

11

12

Double

18

1

3

36

0

5

120

6

10

36

4

5

96

7

8

180

12

13

Identification number of OC curves

Comparable sampling

N and R4

N5

N6

plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

315

19

20

500

28

29

800

42

43

Double

168

7

13

228

8

17

348

21

22

516

29

30

nc = Cumulative sample size. Ac = Acceptance number. Re = Rejection number.

TIGHTENED INSPECTION PLANS—SAMPLING PLANS AND OPERATING CHARACTERISTIC (OC) CURVES FOR AQL = 4.00 DEFECTS PER HUNDRED UNITS

[Sampling plans—AQL = 4.00]

Identification number of OC curves

Comparable sampling

1

2

3

plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

168

7

8

315

13

14

500

18

19

Double

120

3

7

168

5

10

228

5

11

180

8

9

348

14

15

516

19

20

Identification number of OC curves

Comparable sampling

4

5

plans

nc

Ac

Re

nc

Ac

Re

Single

800

27

28

1,250

41

42

Double

456

12

19

864

29

30

nc = Cumulative sample size. Ac = Acceptance number. Re = Rejection number.

REDUCED AND NORMAL INSPECTION PLANS—SAMPLING PLANS AND OPERATING CHARACTERISTIC (OC) CURVES FOR AQL=2.50 DEFECTS PER HUNDRED UNITS

[Sampling plans—AQL=6.50]

Identification number of OC curves

Comparable sampling

R1

N and R2

N and R3

plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

29

4

5

84

9

10

168

16

17

Double

18

1

4

36

2

7

120

10

14

36

5

6

96

10

11

180

17

18

Identification number of OC curves

Comparable sampling

N and R4

N5

N6

plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

315

28

29

500

42

43

800

64

65

Double

168

12

18

228

15

24

348

31

32

516

43

44

nc=Cumulative sample size. Ac=Acceptance number. Re=Rejection number.

TIGHTENED INSPECTION PLANS—SAMPLING PLANS AND OPERATING CHARACTERISTIC (OC) CURVES FOR AQL=6.50 DEFECTS PER HUNDRED UNITS

[Sampling plans—AQL=6.50]

Identification number of OC curves

Comparable sampling

1

2

3

plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

168

11

12

315

19

20

500

28

29

Double

120

6

10

168

7

13

228

8

17

180

12

13

348

21

22

516

29

30

Identification number of OC curves

Comparable sampling

4

5

plans

nc

Ac

Re

nc

Ac

Re

Single

800

42

43

1,250

63

64

Double

456

21

28

864

44

45

nc=Cumulative sample size. Ac=Acceptance number. Re=Rejection number.

REDUCED AND NORMAL INSPECTION PLANS—SAMPLING PLANS AND OPERATING CHARACTERISTIC (OC) CURVES FOR AQL=10.00 DEFECTS PER HUNDRED UNITS

[Sampling plans—AQL=10.00]

Identification number of OC curves

Comparable sampling

R1

N and R2

N and R3

plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

29

5

6

84

13

14

168

23

24

Double

18

2

5

36

3

9

120

14

19

36

6

7

96

15

16

180

25

26

Identification number of OC curves

Comparable sampling

N and R4

N5

N6

plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

315

41

42

500

62

63

800

95

96

Double

168

19

26

228

23

34

348

45

46

516

64

65

nc = Cumulative sample size. Ac = Acceptance number. Re = Rejection number.

TIGHTENED INSPECTION PLANS—SAMPLING PLANS AND OPERATING CHARACTERISTIC (OC) CURVES FOR AQL = 10.00 DEFECTS PER HUNDRED UNITS

[Sampling plans—AQL = 10.00]

Identification number of OC curves

Comparable sampling

1

2

3

plans

nc

Ac

Re

nc

Ac

Re

nc

Ac

Re

Single

168

16

17

315

28

29

500

42

43

Double

120

10

14

168

12

18

228

15

24

180

17

18

348

31

32

516

43

44

Identification number of OC curves

Comparable sampling

4

5

plans

nc

Ac

Re

nc

Ac

Re

Single

800

64

65

1,250

96

97

Double

456

32

41

864

69

70

nc = Cumulative sampling size. Ac = Acceptance number. Re = Rejection number.

1  Includes matters within the responsibility of the Federal Grain Inspection Service.
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Cite this article: FindLaw.com - Code of Federal Regulations Title 7. Agriculture § 7.42.140 Operating Characteristic (OC) curves for on-line sampling and inspection - last updated October 02, 2022 | https://codes.findlaw.com/cfr/title-7-agriculture/cfr-sect-7-42-140/

Read this complete Code of Federal Regulations Title 7. Agriculture § 7.42.140 Operating Characteristic (OC) curves for on-line sampling and inspection on Westlaw

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