An instrument for measuring the long term quality of electrical connecting devices is described. The parameter which controls this property is the contact resistance. In the instrument described, the contact and bulk resistance are separated by utilizing the difference in thermal response time between a contact spot and bulk metal. The circuits, mode of operation, and applications of the instrument are discussed. Contact resistance can be measured within 5% in most electronic connectors, switches, and relays.

1.
R. Holm, Electric Contacts Handbook (Springer‐Verlag, Berlin, 1958), 3rd Ed., p. 2.
2.
C. E.
Skov
and
E.
Pearlstein
,
Rev. Sci. Instr.
35
,
962
(
1962
);
L. A.
Rosenthal
,
Rev. Sci. Instr.
36
,
1179
(
1965
);
and
T.
Guldbrandsen
,
N. I.
Meyer
, and
J. Schjaer
Jakobsen
,
Rev. Sci. Instr.
36
,
743
(
1965
).
3.
J. A.
Greenwood
and
J. B. P.
Williamson
,
Proc. Roy. Soc. (London)
246
,
13
(
1958
).
4.
R. F. Snowball, Trans. Am. Soc. Quality Control Technical Meeting, New York, 452 (1966).
5.
F. P.
Bowden
and
J. B. P.
Williamson
,
Proc. Roy. Soc. (London)
246
,
1
(
1958
).
6.
H. P.
Fink
and
H.
Korner
,
Wiss. Veroffentl. Siemens‐Werk
19
, (
1
),
280
(
1940
).
7.
M.
Kohler
and
G.
Zielasek
,
Abhandl. Braunschweig. Wiss. Ges.
4
,
117
(
1952
).
This content is only available via PDF.
You do not currently have access to this content.