« ÎnapoiContinuați »
ject limits apply, the term "high-sided specification" may be used.
Two-sided specification. A specification with both upper and lower rejection limits applicable.
Sample. Any number of sample units to be used for inspection of a lot.
Sample unit. A container, the entire contents of a container, a portion of the contents of a container, a composite mixture of a product, or any other unit of container or commodity to be used for inspection.
Sampling allowance. The amount that the sample quality may deviate from the lot quality due solely to the fact that only a portion has been taken from the whole lot.
Subgroup. Generally a small group of sample units representing a portion of a sample. The term “subgroup” is synonymous with the term "sample" when the sample contains only one subgroup.
Variable. Any measurable product characteristic. (38 FR 10447, Apr. 27, 1973; 38 FR 12729, May 15, 1973. Redesignated at 42 FR 32514, June 27, 1977 and at 46 FR 63203, Dec. 31, 1981)
(2) The X values;
(3) The total values of all the X values in the subgroups when conventional averages are used;
(4) The values for MI, R, Å, MI, X, and X.
(c) and R control charts. Control charts consist of an å chart and may consist of an R chart. When both are used they are contained on the same sheet with the limits for the Š chart on the top portion and the limits for the R chart on the lower portion with a space separating the two such that plottings from one does not overlap those of the other. Separate control charts shall be maintained for each item. More than one day's production of an item may be plotted on a single control chart.
(1) X charts. (1) The X charts for twosided specifications shall consist of lines and values properly representing both the upper and lower reject and warning limit(s), and may require the use of minimum and maximum specification lot averages.
(ii) The X chart for one-sided specifications shall consist of lines and values properly representing, as applicable, the upper or lower reject and warning limit(s), and the minimum or maximum specification lot average.
(2) R charts. When the R chart is used, it shall consist of lines and values properly representing R’, Rmax, and the lower limit for R. For subgroup sizes of 6 or less the value of the lower limit for R will always be zero. (38 FR 10447, Apr. 27, 1973; 38 FR 12729, May 15, 1973. Redesignated at 42 FR 32514, June 27, 1977 and at 46 FR 63203, Dec. 31, 1981)
(a) General. Records required for use in the implementation of these standards consist of a data sheet, referred to as an "X and R data sheet,” on which numerical values are recorded, and/or a control chart on which certain numerical values are recorded in the form of plottings. It is desirable to use both forms. The control chart may be incorporated on the same sheet with the X and R data sheet. However, one of these forms may be used in lieu of both as desired at the option of the packer.
(b) X and R data sheets. A separate data sheet shall be maintained for each item. When a single item is simultaneously produced on more than one processing line, it is desirable to maintain one data sheet for the item. In such instances, the processing line designation shall be recorded with the corresponding data.
The X and R data sheets shall provide for recording the following information:
(1) The time a sample unit or subgroup has been drawn;
(a) General. In order to obtain the most reliable results, sampling should be performed at a point where no further change in the variable can occur. Sample units or subgroups shall be drawn separately for each code, container size, and style.
(b) Subgroup sampling. Sampling by subgroups consists of drawing more than one sample unit at approximately the same time. This type of sampling is required in the use of the conventional Å and R determinations for variables.
as prescribed under $52.209(a) of these (111) Mi or X is equal to or less than standards.
X'mas adjusted and equal to or greater (38 FR 10447, Apr. 27, 1973; 38 FR 12729. May
than X'min adjusted; and 15, 1973. Redesignated at 42 FR 32514. June 27,
(iv) The condition under paragraph 1977 and at 46 FR 63203, Dec. 31, 1981)
(a)(2)(11) of this section does not exist.
(2) Rejection. A lot shall be rejected 852.208 Application of sampling allow- for failure to meet specified require
ments for a variable under the followThe amount of sampling allowance is ing conditions: obtained from the sampling allowance (i) Failure to meet any of the rechart in these standards. The actual quirements under paragraph (a)(1), (i). value for the sampling allowance is ob- (11), or (iii) of this section; or tained from the point of intersection of (11) All Mi or X values are less than a horizontal line drawn from a point on X
'mio or greater than X, the vertical axis representing the sam- (b) Moving averages (1) Acceptance. A ple size to the diagonal line for the lot shall be accepted as meeting speciitem involved. The value on the hori- fied requirements for a variable prozontal axis corresponding to the verti- vided that: cal line nearest to this point of inter- (1) All X values are equal to or greatsection is the sampling allowance. er than LRL and equal to or less than The sampling allowances are applied to URL; the specified lot averages to allow for (11) All X values are equal to or greatdeviations from these averages that are er than LRL, and equal to or less than inherent in any sampling procedure. URLxi. These allowances are applied to the (111) X is equal to or less than Xmas specified lot averages: only when the adjusted and equal to or greater than sample average (x or Mi) is less than I'min adjusted; and Xmia or greater than X'mar. When this (iv) The condition under paragraph occurs, the specification average is ad- (b)(2)(ii) of this section does not exist. justed by subtracting the allowance (2) Rejection. A lot shall be rejected from Åmin or adding to Xmas, which- for failure to meet specified requireever is applicable.
ments for a variable under the follow
ing conditions: 852.209 Acceptance and rejection cri.
(1) Failure to meet any of the condi. teria.
tions under paragraph (b)(1) (i), (11), (a) Conventional averages and the me- and (iii) of this section; or dian-(1) Acceptance. A lot shall be ac- (11) All Å values are less than å min or cepted as meeting specified require- greater than X'mas. ments for a variable provided that: (1) All X values are equal to or great
(38 FR 10447. Apr. 27. 1973; 38 FR 12729, May
15, 1973. Redesignated at 42 FR 32514, June 27, er than LRL and equal to or less than
1977 and at 46 FR 63203, Dec. 31, 1981) URL; (11) All Mi or X values are equal to or
SAMPLING ALLOWANCE CHART greater than LRL, and equal to or less than URLxi
$ 52.210 Sampling allowance chart
(a) The variables inspection standards may be used, where applicable, by any food processor for quality control purposes. Certification by the U.S. Department of Agriculture (USDA) of fill weights based on these standards, however, is applicable only under on-line inspection when a USDA inspector is present at time of packing and maintains appropriate records of the filling process.
(b) The procedure for determination and certification of fill of container, based on drained weights, may be used in the case of lot inspection as well as in-line inspection. This procedure, where applicable, is outlined in the U.S. standards for the respective products.
852.225 Preparation of forms.
(a) Prepare the data sheet and control charts prior to the start of a processing period. Draw lines representing the X'min, LRLx, and LRL values applicable for the product, container size, and style on the appropriate linear segment of the X chart in such a manner as to be clearly visible when posted in the plant. Lines representing LWLX and LWL may be drawn on the chart at the option of the user; how- ever, all the values representing each limit (Xmin, LWLX, LRLx, LWL and LRL) are placed on the X chart adjacent to the appropriate limit and identified (in brief form) as X, WLX, RLX, WL, or RL accordingly).
(b) When the R chart is used, it is desirable to place it on the lower portion of the control chart, using the bottom as zero, which is the lower limit for R.
(c) Space the limits for R' and Rmax on the appropriate linear segment above the zero line. The upper portion of the control chart is then used for the å chart.
(d) Attachment 1 is an example of an X and R data sheet. Attachment 2 is an example of a control chart which combines the X chart and the R chart. However, use of the R chart is not required. The X chart illustrates the use of the median option as prescribed in the proposed U.S. Standards for Inspection by Variables. The dots plotted on the X chart represent the X values for the subgroup. The encircled dot rep resents the median of each subgroup. For easier identification the circle