Electromagnetic Radiation Threat to Electroexplosive Devices

DOE-HDBK-1092-98

EM radiation-safe levels have been established by the Institute of Electrical and Electronics

Engineers and are documented in the IEEE standard - C95.1-1991.

Exposure to hazardous levels of EM radiation can be lessened by maintaining as much distance as

possible from the source. Power density is reduced by a factor of four by doubling the distance from

the source.

9.13.2 ELECTROMAGNETIC RADIATION THREAT TO ELECTROEXPLOSIVE

DEVICES

Designers of enclosed electrical/electronic equipment must consider the possible effects on nearby

electroexplosive devices (EED) of electromagnetic radiation (EMR), i.e., radio frequency (RF)

energy, emitted by that equipment.

Energy induced into an EED by the electromagnetic field resulting from such emissions may be

adequate to cause the device to detonate.

Factors which should be taken into account in assessing concerns for possible EMR emissions are:

Wiring, shielding, and sensitivity

Proximity

Frequency of the emissions causing coupling of electrical energy

Power density

Type of emission modulation

Possible measures to mitigate the threat of EMR emissions include:

1. Enclosure and signal line shielding and grounding to prevent leakage of EMR from the

equipment.

2. Designed-in physical separation or barrier which would ensure that the power density of the

electromagnetic field is inadequate to cause detonation of an EED at the closest possible

distance to the emission source within the equipment.

3. Filter, or provide ferrite beads for, signal lines from the equipment which may conduct EMR

emissions into EED circuitry or secondarily radiate EMR in the proximity of an EED thus

causing a threat of detonation.

4. Ensure that the minimal power necessary is used to operate circuitry capable of producing

EMR.

5. Label the equipment capable of emitting EMR to indicate the minimum separation distance

to be maintained between the equipment and an EED(s).

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