MIL-PRF-20M
4.7.8 Temperature coefficient and capacitance drift (see 3.12).
4.7.8.1 For qualification inspection.
4.7.8.1.1 Temperature coefficient. Capacitance measurements shall be made as specified in 4.7.3 and at the
temperatures specified in table IX.
4.7.8.1.2 Capacitance drift. Capacitance drift shall be computed by dividing the greatest single difference between
any two of the three capacitance values recorded at 25°C by the value determined at the reference temperature (see
table IX).
TABLE IX. Temperature coefficient and capacitance drift.
Temperature, °C
Temperature, °C
Step
Step
A
+25 +0, -2
G
+65 +2, -0
B
-55 +0, -2
H
+85 +2, -0
C
-40 +0, -2
I
1/ +105 +2, -0
D
-10 +0, -2
J
1/ +125 +2, -0
E (reference)
+25 +0, -2
K
+25 +0, -2
F
+45 +2, -0
1/ Applicable to +125°C capacitors.
The measurement at each temperature shall be recorded when two successive readings taken at 5 minute intervals
at that temperature indicate no change in capacitance. The accuracy of capacitance increments shall be within
±0.005 pF. For capacitors with values of 20 pF or less, the temperature coefficient tolerance shall be as specified
(see 3.1).
4.7.8.2 For conformance inspection.
4.7.8.2.1 Temperature coefficient. Capacitance measurements shall be made as specified in 4.7.8.1.1, except that
measurements shall be made at +25°C +0°C, -2°C; -55°C +0°C, -2°C; +25°C +0°C, -2°C (reference temperature);
+85°C +2°C, -0°C; +125°C +2°C, -0°C (if applicable, see 3.1); and +25°C +0°C, -2°C, respectively, and the values so
determined shall be checked against the known shape of the curve for the dielectric material used, as determined in
more complete tests.
4.7.8.2.2 Capacitance drift. Capacitance drift shall be computed as specified in 4.7.8.1.2.
4.7.9 Shock, specified pulse (see 3.13). Capacitors shall be tested in accordance with method 213 of
MIL-STD-202. The following details shall apply:
a. Mounting: Capacitor shall be rigidly mounted by the body.
b. Test condition I: (100 g's).
c. Measurements during shock: During the last shock in each direction, an electrical measurement shall be
made to determine intermittent contacts of 0.5 ms or greater duration or open-circuit or short-circuiting.
d. Examination after shock: Capacitors shall be visually examined for evidence of breakdown, arcing, and
mechanical damage.
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