ANSI EIA 364-69A-2002 pdf download Low Level Induction Measurement for Electrical Contacts of Electrical Connectors
4 Test procedure Unless otherwise specified in the referencing document, the test frequency(s) should be in the recommended area shown in figure 1. The plot identifies the minimum frequency to ensure the minimum 5 ohms inductive reactance required to minimize measurement error using typical 50 ohm measurement equipment. The test professional should be aware of the limitations and associated accuracy levels when measuring values below 20 nanohenrys. Place the specimen a minimum of 5 cm from any objects that would affect measured results.
4.1 The inductance of at least three specimens shall be measured unless otherwise specified in the referencing document. In the case of multi-contact connectors, at least three specimens of each type of contact from at least three connector specimens shall be measured unless otherwise specified in the referencing document. For pin and socket contacts the depth of engagement shall be the nominally designed engagement depth unless specified in the referencing document.
4.2 The point of measurement shall be between the termination points of the specimen as shown in figure A.1.
4.3 Adjust the spacing of the test fixture test points to accept the specimen.
4.4 Remove the specimen from the fixture, and in its place insert a round rod of known diameter having a length equal to that of the test sample. The rod diameter should be chosen to yield a calculated value slightly lower than that expected for the specimen.
4.4.1 The reference rod shall remain straight at all times. The calculation of inductance for the reference rod is based on a straight conductor.
4.4.2 When measuring a 90 degree specimen as shown in Figure A.1.C, the straight reference rod is to be installed diagonally on the test fixture, contacting the test fixture at the same points that the test sample will contact when it is installed in place of the rod. NOTE  The test requestor should be aware that the value obtained from a 90 degree specimen (or any non collinear specimen) may not be accurate due to coupling with the fixture conductors.
4.5 Use the formula given in annex A to calculate the self inductance of the reference rod.
4.6 Set the test equipment to the desired measurement frequency.
4.7 Zero the RLC meter or inductance meter with the instrument set for a resolution of 0.1 nH.
4.8 Remove the reference rod and replace it with the test specimen without disturbing the position of the test fixture conductors or the settings of the RLC meter.
4.9 Record the value indicated by the RLC meter. The inductance of the test specimen is the sum of this value plus the inductance of the reference rod determined in 4.5.