IPC-TM-650 EN 2022 试验方法.pdf - 第17页
The following guidelines should be used for numerical report- ing: 1. Follow the IPC policy for the use of metric and English units. In an effort to prepare the industry for a full change to complete metric measurements …
Recommendations
If
applicable and if possible, this section is used to recom-
mend needed corrections or to indicate discrepancies in the
design of the specimen, which was tested. Care should be
taken to limit the recommendations to those things indicated
by the test, and not go into design problems, which are the
responsibility of the designer.
IPC-TM-650
Number
1.5
Subject
Reporting,
Format
Date
01/03
Revision
A
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The
following guidelines should be used for numerical report-
ing:
1. Follow the IPC policy for the use of metric and English
units.
In an effort to prepare the industry for a full change to
complete metric measurements in IPC standards and
specifications, the Technical Activities Executive Commit-
tee (TAEC) voted on a new way for both to be included.
Through this new metric conversion policy, IPC docu-
ments will have hard metric numbers and parenthetical
soft imperial numbers with appropriate units.
The hard metric numbers will represent accuracy of the
numerical values as decided by the working committee/
task group according to their respective contexts.
For
example:
The
working committee/task group will decide whether a
hard metric number should be represented as:
1.3 mm (any value within the range of 1.25 mm to 1.34
mm is acceptable), or
1.30 mm (any value within the range of 1.295 mm to
1.304 mm is acceptable).
The soft imperial numbers will have one significant digit
more than the metric numbers to capture the accuracy
represented by the metric numbers.
For
example:
3m(one
significant digit) converts to 118.1102 in, which
will be documented as 3 m [120 in] (two significant dig-
its because the zero is a placeholder).
3.0 m (two significant digits) converts to 118.1102 in,
which will be documented as 3.0 m [118 in] (three sig-
nificant digits).
9.17 m (three significant digits) converts to 30.0853 ft,
which will be documented as 9.17 m [30.09 ft] (four sig-
nificant digits because all zeros embedded between non-
zero digits are significant).
2mm(one significant digit) converts to 0.07874016 in,
which will be documented as 2 mm [0.079 in] (two sig-
nificant digits because the zeros are placeholders used to
locate the decimal point).
66 µm (two significant digits) converts to 0.002598425 in,
which will be documented as 66 µm [2.60 mil] (three
significant digits because the non-truncated zero is not a
placeholder).
725 µm (three significant digits) converts to 0.02854331
in, which will be documented as 725 µm [28.54 mil] or
[0.02854 in] (appropriate units are determined by the
context of numerical values and both have four significant
digits).
3.8X10
-6
m
converts to 1.496063 X 10
-4
in,
which will
be documented as 3.8X10
-6
m [1.50 X 10
-4
in] (if sci-
entific numerical format is appropriate).
2. Spell out numbers one through ten, except in use with
measurement and time.
3. Spell out any numbers at the beginning of a sentence.
4. When reporting numbers less than a whole number,
place a zero to the left of the decimal point.
5. Report average results to the same amount of significant
figures as the numbers being averaged.
6. When readings reach maximum of test equipment or
maximum of practical values, precede the number with
‘‘greater than’’ or ‘‘>’’ and explain the reason for not
going to the limit.
7. Always report results in the same unit of measurement as
that of the requirement.
8. In reporting ranges use the preposition ‘‘to,’’ not a
hyphen as: 3 cm to 9 cm.
9. Report portions of a unit of measure in the singular.
10. Mark a failed result in such a way as it will stand out to
the reader. Later state what this marking signifies.
11. When tabulating, use clearly defined headings.
12. Clarify when more than one set of numbers is in a tabu-
lation of statement.
2215
Sanders Road
Northbrook, IL 60062-6135
IPC-TM-650
TEST METHODS MANUAL
Number
1.6
Subject
Numerical
Reporting
Date
01/03
Revision
A
Originating Task Group
N/A
Material
in this Test Methods Manual was voluntarily established by Technical Committees of IPC. This material is advisory only
and its use or adaptation is entirely voluntary. IPC disclaims all liability of any kind as to the use, application, or adaptation of this
material. Users are also wholly responsible for protecting themselves against all claims or liabilities for patent infringement.
Equipment referenced is for the convenience of the user and does not imply endorsement by IPC.
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ASSOCIATION CONNECTING
ELECTRONICS INDUSTRIES
®
In
interpreting test results, it is essential that all values are
known to be valid. Usually the values are placed in one of the
three following categories and evaluated to ultimately arrive at
a sound decision:
a. Results are declared valid. A decision can be made imme-
diately
b. Results obviously must be discarded. Specimens that
break or otherwise fail because of some obvious flaw, or
that do not behave in the same general manner as the
other specimens, should be discarded. Retests should be
performed on new specimens.
c. Results deviate from the mean value. All test data obtained
from properly performed tests must be included in deter-
mining mean and standard deviation unless there is an
assignable cause not to do so.
The above information is to be used if not found in an indi-
vidual test method.
2215
Sanders Road
Northbrook, IL 60062-6135
IPC-TM-650
TEST METHODS MANUAL
Number
1.7
Subject
Reporting,
Invalid Test Results
Date
01/03
Revision
A
Originating Task Group
N/A
Material
in this Test Methods Manual was voluntarily established by Technical Committees of IPC. This material is advisory only
and its use or adaptation is entirely voluntary. IPC disclaims all liability of any kind as to the use, application, or adaptation of this
material. Users are also wholly responsible for protecting themselves against all claims or liabilities for patent infringement.
Equipment referenced is for the convenience of the user and does not imply endorsement by IPC.
P
age1of1
ASSOCIATION CONNECTING
ELECTRONICS INDUSTRIES
®