Information

108-40030
Rev A 4 of 6
4. QUALITY ASSURANCE PROVISIONS
4.1. Qualification Testing
A. Sample Selection
Connector housings and contacts shall be prepared in accordance with applicable
Instruction Sheets. They shall be selected at random from current production. All test groups
shall consist of a minimum of 6 double ended cable assemblies of each type (HDE-20 and
HDP-20) with shielding hardware crimped on but not overmolded. The cable shall be constructed
as follows:
1. 0.032 inch maximum single jacket, 75 to 80 shore durometer
2. Overall tinned copper braid, 90% coverage.
3. Overall foil shield with drain wire
4. The above items constitute approximately 88% of the cross sectional area of the cable
5. All contacts terminated.
Each cable assembly shall have a cable length of 6 feet + .5 inch between the connector back
shells as specified in Test Specification 109-90.
B. Test Sequence
Qualification inspection shall be verified by testing samples as specified in Figure 2.
C. Acceptance
1. Test results from development on pre-qualification samples will be used to determine upper
and lower one-sided statistical tolerance limits for 99% reliability at 95% confidence, as
follows. Let Xbar and s denote the sample average and standard deviation, respectively, of
the test data. Let k denote the normal distribution one-sided tolerance factor for 95%
confidence and 99% reliability. The value of k varies with sample size. Values of k are
given in various tables, for example, NBS Handbook 91, Factors for One-Sided Tolerance
Limits for Normal Distribution. Suitability of the normal distribution for representing the
data shall be verified with normal probability plots, goodness of fit tests, etc.
Then the upper one-sided tolerance limit for 99% reliability at 95% confidence is given by
Xbar + ks. The interpretation of thistolerance limit is as follows: based on the test
data, and assuming a normal distribution for the test data, we can be 95% confident that
99% of the population of values represented by the sample data will not exceed Xbar + ks.
For any test parameter for which there is specified an upper requirement which is not to be
exceeded, satisfactory performance of the product is achieved when the value of Xbar + ks
does not exceed the requirement value.
The lower one-sided tolerance limit for 95% confidence and 99% reliability is given by
Xbar - ks. This has a similar interpretation and corresponding application to lower
requirement values.
2. Failures attributed to equipment, test setup, or operator deficiencies shall not
disqualify the product. When product failure occurs, corrective action shall be taken
and samples resubmitted for qualification.
4.2. Requalification Testing
Requalification shall be established by the cognizant divisional engineering function and may
consist of all or any part of the overall qualification program provided that it is conducted within the
required time period.
4.3. Quality Conformance Inspection
The applicable quality inspection plan will specify the sampling acceptable quality level to be used.
Dimensional and functional requirements shall be in accordance with the applicable product drawing
and this specification.