Rules for expression and judgement of limiting values

This standard specifies the method of writing limit values, the meaning of relevant terms, and the method of comparing the measured value or its calculated value with the limit values ​​specified in the standard. This standard applies to the compilation of standards at all levels and the determination of test results. GB 1250-1989 Method of expressing and determining limit values ​​GB1250-1989 standard download decompression password: www.bzxz.net
This standard specifies the method of writing limit values, the meaning of relevant terms, and the method of comparing the measured value or its calculated value with the limit values ​​specified in the standard. This standard applies to the compilation of standards at all levels and the determination of test results.

National Standard of the People's Republic of China
Rules for expression and judgement of limiting values
t Subject content and scope of application
UDC519.214
G8 1250 --89
This standard specifies the method of writing limiting values, the meaning of relevant terms, and the method of comparing the measured value or its calculated value with the limiting value specified in the standard.
This standard is applicable to the compilation of standards at all levels and the judgment of test results. 2 Referenced standards
G8170 Rules for rounding off values
3 General principles for writing limiting values
3.1 The indicators or parameters given in quantitative form in the standard shall specify the limiting values, which represent the limits of the numerical range that meets the requirements of the standard, and are expressed by giving the minimum limiting value and (or) the maximum limiting value, or giving the basic value and the limiting deviation value. 3.2 The representation form and number of digits of the limit value in the standard should be appropriate. All its significant digits should be written out. The degree of accuracy expressed by the number of digits written should be able to ensure the proper performance and quality of the product or other standardized object, so it also stipulates the corresponding degree of accuracy that the measured value or its calculated value obtained for testing the actual product or other standardized object should have. 4 Terms and meanings of limit values
4.1 Basic terms and meanings
Basic terms and their gradual meanings for expressing limit values ​​are shown in Table 1. Table
Terms used in the table
Less than A
Greater than or equal to A
Less than or equal to A
Example 1: Residual components (magnesium, etc.)
Example 2: Tensile strength (MPa)
Basic terms for specific situations
More than A
Less than A
Not less than A
Not less than A
36×04
Not less than FA
Not more than A
4.1.2 Basic terms can also be used in combination; used to indicate the range of limiting values. a: 15Mn steel grade composition
approved by the Technical Supervision Bureau in 1989-0322
higher than A
lower than A
not waiting for A
not higher than A
A value does not meet the standard requirements
A value meets the standard requirements
Value meets the standard requirements
1989-10-01 implementation
GB 1250--89
Not less than
Not greater than
4.1.3 "Not more than ten", "not less than", "more than", "less than" and other terms should be used to describe time, distance indicators, and counting indicators that only take integer values.
Example: The service life is not less than 300h.
4.1.4 "Not higher than", "not lower than", "higher than", "lower than" and other terms should be used to describe the diffusion, height (with upward as the positive direction) indicators and other occasions,
Example 1: The flash point of light diesel used in main and auxiliary engines should not be lower than 60℃:, Example 2H The oil outlet pipe of the oil tank should be 80mm from the bottom of the cabinet, 4.2 Allowed customary terms and their meanings|| tt||When necessary, the following terms are allowed.
4.2, FA and above\, index value is greater than or equal to FA (A): \A and below\, index value is less than or equal to A (A) 4.2.2 "Exceeding A\. Index value is greater than A (>1), less than 4\. Index value is less than M (<4): \At most A\. Index value is less than or equal to FA (grade A) "At least A index value is greater than or equal to A (2A). 4.2.3 For a certain assessment indicator ×, the following terms and symbols are allowed (see Table 2). Generally, only one row number representation method should be used in the same standard:
Allowed terms
From A to B
Exceed A
At least less than
Exceed A Insufficient B
Expression method.
Expression method
Expression method 3
If a table contains requirements for multiple indicators, the maximum and minimum can be used as table headers when necessary: ​​"Maximum: A\index\≤A", 4. 2. 4
“Minimum: 1\ refers to “A\, 4 belongs to the standard requirements. If the limit values ​​of individual indicators in the table have exceeded the standard requirements, they should be enclosed in brackets and written as \B (excluding)”. When B is under the “minimum\ column, it can be written as ">B”, and when B is under the “maximum\ column, it can be written as \B”. 4.3 Values ​​with limit deviation values ​​and their implications 4.3.1 A basic value A has an absolute upper limit deviation value +b: and an absolute lower limit deviation value -b:, that is, 4, which means that from (4-b2> to (A+6) meets the standard requirements.
Example: 80!mm, which means that from 79mm to 82mm meets the standard requirements. 4.3.2 A basic value A has a relative upper limit deviation value +% and a relative lower limit deviation value -%, that is, 4%, which means that the relative deviation value (R=A)/AI of the measured value or its calculated value R to A ranges from -% to +% and meets the standard requirements. Example: 51052=5%, which means that the relative deviation value [(R-510)/510 from -5% to +5% of the measured value or its calculated value () to 5102 meets the standard requirements.
4.3.3 If the basic limit difference B exceeds the standard requirements, brackets should be added and written as \B(excluding B)\. Example 1: 80t excluding 2) mm, which means that from 79mm to close to but less than 82mm meets the standard requirements. Example 25102=5% (not including 5%), refers to the relative deviation value of the measured value or its calculated value R (2) for 51052 [(R-510)/510 from -5% to close to but less than +105% meets the standard requirements, GB 125089
5 Method for comparing the measured value or its calculated value with the limit value specified in the standard 5.1 Two judgment methods
5.1.1 When judging whether the test data meets the standard requirements, the measured value or its calculated value obtained by the test should be compared with the limit value specified in the standard. There are two comparison methods: rounded value comparison method:
b full value comparison method,
5.1.2 There is a type of limit value that is an absolute limit, written as 20.2 and written as 20.20 ≥ 0.200, which has the same meaning on the limit. For this type of limit value, the measured value or its calculated value is used to judge whether it meets the requirements. The full value comparison method should be used. 5.1.3 For numerical values ​​with extreme deviation values, indicators involving safety performance indicators and indicators with error transmission in measuring instruments or other important indicators, the full numerical comparison method should be used as a priority. 5.1.4 All the limit values ​​(including those with limit deviation values) in the standard, unless otherwise stated, refer to the full value comparison method: If the rounded value comparison method is specified, it should be stated in the standard: 5.2 Rounded value comparison method
5.2.1 The measured value or its calculated value shall be rounded off, and the rounded digit shall be consistent with the digit written in the limit value currently specified in the standard. Rounding shall be carried out in accordance with GB8170.
5.2.2 Compare the rounded value with the limit value specified in the standard to determine whether the actual index or parameter meets the standard requirements. See Table 3 for examples.
Tensile strength
Oleic acid
mg KOH/g oil
Wire rod diameter
Limit value
56×10
0. 30--0. 60
(Limit deviation ± 0.5)
Measured value or calculated valueWww.bzxZ.net
Note: The indication in the table does not mean that all such limit values ​​should be compared by the rounded value method. 5.3 Full value comparison method
Rounded value
55: 10
56 ×10
Whether it meets the standard
The measured value or calculated value obtained by the test is not rounded off (or it can be rounded off, but it should be indicated whether it is obtained by rounding off, rounding up or not - see G8170) and all the digits of the value are compared with the limit value specified in the standard. As long as it exceeds the specified limit value (regardless of the degree of the excess), it is judged as not meeting the standard. Examples are shown in Table 1. Item
Tensile strength
NAUH content,
Superior purity
Silicon content
Silicon content
Polarity
56×xto
0. 30~0. 60
10, 0 ± 0.1
GB 125089
Measured value or calculated value
Note: ① The examples in the table do not indicate that such limited values ​​should be written by full value comparison method or
56×10(—)
56×[0(—)
56×10
56×104
0. 05( —)
0. 30(— )
0. 606 13
3. 96 -.
For the limit effect of the sample, if it belongs to the standard requirements, the full value comparison method is stricter than the peak value comparison method. Additional remarks:
This standard is drafted by the China Institute of Standardization and Information Classification and Coding. This standard is drafted by the Institute of Systems Science, Chinese Academy of Sciences. The main drafter of this standard is Wu Chuanyi.
Whether it meets the requirements of the coordination
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