MIL-DTL-19595D
4.2.1.3.5 Special Component Test Distance. A special component test distance is the distance from the
center of the active element in the HSM-2 Magnetometer sensor to the surface of the item as specified in
the applicable engineering drawings and/or specifications.
4.2.1.4 Standard Test Temperature and Earth's Magnetic Field Limits. Magnetic effect measurements
shall be performed at a temperature of 70 " 10EF and in an earth's magnetic field of 44,000 - 56,000
gamma. The field strength is measured when the test item and all other magnetic materials are removed
from the vicinity of the magnetometer sensor.
4.2.1.5 Selection of Reference Axes. Three mutually perpendicular reference axes shall be selected for
each item. The primary reference axis shall be the longest axis of the item, and the secondary reference
axis shall be the longest axis perpendicular to the primary axis. The third reference axis shall be
perpendicular to the primary and secondary axes.
4.2.2 TEST PROCEDURE 2. Test for Magnetic Effects of Electrical Items. The item shall be
demagnetized per 4.3 before testing. The magnetic effects of electrical items shall be measured for each
operational mode. The magnetic effect measurement is the highest reading obtained from any operational
mode. Testing shall be in accordance with 4.2.1.2 and 4.2.2.1.
4.2.2.1 Electrical Item Test Conditions. Fully charged batteries shall be used for these tests. All controls
shall be adjusted for maximum current flow.
4.2.3 TEST PROCEDURE 3. Eddy Current Generated Field Test. The item shall be demagnetized per
4.3 before testing. Each item shall be measured for eddy current generated field as in 4.2.3.1. Procedure
4.2.3.1 shall be performed for each of the three reference axes selected as in 4.2.1.5. The eddy current
generated field measurement is the highest reading obtained from any of the three idealized axes.
4.2.3.1 Eddy Current Generated Field Measurements. The HSM-2 Magnetometer sensor shall be aligned
perpendicular to the earth's magnetic field. At the start of the measurement, the item shall have its
reference axis aligned perpendicular to the earth's magnetic field and passing through the point at which the
eddy current generated field is measured. The initial distance between the item and sensor shall be at least
two feet. It is then moved in a nutational and oscillating motion, about the center of the reference axis, so
that one end of the item moves toward the detector while the other end moves away from the sensor. The
movement will be through an angle of 30E, 15E in each direction from the original position of the item at
the sensor. The rate of movement will be such that 15 complete oscillating cycles occur in 10 seconds. The
item is then brought to test distance. This is repeated for the other two reference axes. After completing
the nutational and oscillating cycles, the item is removed to the starting point. The eddy current generated
field is the sum of the absolute values of the largest plus and minus variations as measured during any
cycle.
4.3 Demagnetization. The test item is placed in the same cycled, pulsed magnetic field used for idealization
(see 4.2.1.1) except that the five gauss field is not present. The square wave is centered about zero gauss,
instead of the five gauss field. The same six second cycle is repeated until the amplitude is reduced to zero.
The test item shall be aligned with the last axis of magnetic idealization. The purpose of demagnetization
is to cancel any magnetically induced fields.
5. PACKAGING
5.1 Packaging. This section is not applicable to this specification.
6. NOTES
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