Testing, operational shields

After the design of the shield has satisfied the requirements, and the prototype shield has been fabricated, reference 1 specifies the testing to which it must be subjected. The prototype operational shield must be tested by creating an MCI in a simulated operational environment. 

Documentation of the tests should also be provided by still photography, video camera/recorder systems, and high speed photography. The high speed photography with a minimum speed of 500 frames per second Is necessary to be able to see any flame front exiting a shield. A list of typical Instrumentation used on an operational shield test Is shown on Table II, (see reference A). 

SUMMARY. The safety record associated with the use of APE operated remotely or within operational shields is excellent. Operational shields that are properly designed, fabricated, and tested do provide operators with adequate protection, and ensures their safety during hazardous operations. 

Miller, J., APE 1011M6 Operational Shield Tests MK39 Primer In Empty 6 lnch/47 Cartridge Case (1340 Grains Black Powder), Ammunition Equipment Directorate, Tooele Army Depot, Tooele, Utah, D/AE Report 05-82, 22 February 1982. 

Experiments and even production operations can be conducted at any frequency providing the radiated and conducted signals meet the apphcable tfi limits for ISM equipment. Tests to certify this stipulation must be carried out before inception of operations. This implies weU-shielded enclosures at high power levels which is expensive but justified in certain apphcations. 

Rn-222 is produced from a dry Ra-226 source with an activity of about 2 mCi housed in a lead shield. Radon is carried from the source by means of compressed air with a regulated flow rate of 200 cnr/min. The test chamber is operated with a 75 1/min air pump located downstream (Figure 1XDroullard, et al., 1984) that exhausts to the outside of the building. The flow rate of this air pump is monitored by a mass flow transducer whose signals are converted to volumetric flow rates. 

The MCI is created by detonating or igniting a test round(s), or item(s) with all items in the operational configuration in the shield, including the equipment or reasonable simulation thereof, that performs the intended function on the munitions. If the shield is intended to be used for a variety of rounds, the one(s) having the most severe effects for overpressure, fragmentation, thermal emissions and shape charge effects is to be tested. 

The test should also be conducted in a location that simulates the location when it will be specifically used. For example, shields to be used in an operational bay should be tested in a simulation of an operational bay. 

Mll-STD 398 Shields, Operational for Ammunition Operations, Criteria for Design of and Test for Acceptance 5 November 1976. 

A fixture for mechanical function testing is photographed in Figure 6. It Illustrates the attachment of the shield to the barricade. The operator rolls the cart up to the barricade where a clamp is closed and the shield is locked to the barricade. Transport mechanisms shown behind the barricade remove the tray with explosive material from the shield. At no time is the operator exposed to explosive hazards. 

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