Service manual

STP 11-25R13-SM-TG
T - 14
(1) All high-voltage equipment and components will be shielded to protect personnel from electrical
shock. The main power ON-OFF switch located on the equipment (clearly labeled as such) will cut off all
power to the complete equipment.
(2) All charging capacitors will be equipped with bleeder resistors which automatically discharge
the system to 30 volts within 2 seconds or less when not in use. The various methods of discharging the
capacitors will be clearly indicated in maintenance manuals and operating instructions.
NOTE: Some laser devices activate a relay to discharge the capacitor when lid
covers are removed and others when the OFF button is pushed. This type
information must be available to operating and maintenance personnel.
n. Other Safety Precautions.
(1) All laser areas will be ventilated to prevent accumulation of ozone, nitrogen, hydrogen, or other
toxic or flammable gases that may result from high-voltage or chemical sources. Also, the ventilation will
insure an adequate oxygen supply in the event of a discharge of coolant from a cryogenic system, and to
minimize hazards from toxic or infectious fumes.
(2) Personnel required to handle cryogenic materials will be protected by face shields, gloves, and
three-quarter length smocks. Cryogenic materials will not be handled during lasing operations. If
cryogenic gases leak into a closed room, they are capable of replacing oxygen in the atmosphere and
possibly causing asphyxiation.
(3) Eye bath fountains and/or showers will be installed in laser facilities where hazardous
chemicals or chemical equipment are used.
(4) Combustible solvents and materials associated with laser operations will be handled and stored
to prevent ignition.
o. Eye Examinations. All personnel who will be exposed to laser radiation will be given eye
examinations in accordance with TB MED 279 before initial exposure, at the intervals specified by the
responsible medical officer, and upon termination of employment.
p. Placards. Caution or danger placards with the type laser in use will be properly posted (ANSI-
Z136.1-1973).
T-20. Microwave Radiation.
a. Personnel associated with the development, calibration, or maintenance of microwave
equipment will comply with TB MED 523 which outlines the precautions to be taken when working with
microwave equipment. TB MED 523 outlines the power density limits to be used for controlling personnel
exposure. This manual specifies that power densities between 10 and 100 milliwatts per square
centimeter (mW/cm
2
) are potentially hazardous with limited exposure permitted, and intensities of 100
mW/cm
2
, or greater, are to be considered as DENIED exposure levels. Please understand that
hazardous levels of microwave radiation can be emitted from so-called low-power generating sources; for
example, a microwave generator with a power output of 100 mW will generate a power density load of
100 mW/cm
2
when the energy is concentrated over a 1 square centimeter area. Such an area could be
the open-ended waveguide of the microwave generator. Since exposure to microwave radiation can
cause eye damage, as well as affect other areas of the body, certain precautions must be followed:
(1) Personnel working in the vicinity of microwave or radio frequency (RF) generating equipment
should be informed as to the potential personnel health hazards associated with exposure to the energy
being radiated from such equipment.