Uncontrolled environments

Fig. 5. Long-term magnetic field exposure limits for general public exposures in uncontrolled environment, where A is the 50/60 Hz window, according to B, IRPA C, VDE (Germany) D, NRPB (U.K.) and E (IEEE C95.1, 1991). To convert T to G, multiply by 10/...

Prior to the start of any production activity, materials and components must be transferred from a warehouse environment into a classified environment. For most items this will necessitate removal from boxes or cartons, transfer to a nonwooden pallet, and passage through an air lock which serves as the transfer system between the controlled and uncontrolled environments. Often components are contained within plastic bags within a box or carton, and in some cases there are multiple bag layers to facilitate disinfection and passage through air locks into different zones of operation within the aseptic area. The firm may utilize an external disinfection of the materials in conjunction with this transfer. The concern is for minimization of particles and bioburden on these as yet unprocessed items in order to protect the controlled environment. 

Electronic Diary Cards are portable, hand-held systems designed to be programmed according to specific protocol requirements and are used by patients to record directly information on their condition and medication consumption during a particular study. They should be specified and designed so that they are highly prescriptive since they are used in a relatively uncontrolled environment (e.g., subject s home). Specific considerations for the validation of electronic diary cards are ... 

FIGURE 22.7 ANSI/IEEE C95.1 -1992 radio frequency protection guide. Guidelines for controlled environments in plain text guidelines for uncontrolled environments in italics. 

In the real world, metals are seldom exposed to controlled environments. Thus, the development of materials for use in the real world normally requires exposure studies in uncontrolled environments. 

Generally not recommended even though initial results may be positive, extended storage in an uncontrolled environment prior to assembly could lead to problems. 

In order to relate Fig. 6.8 to the conditions likely to be encountered in service, the shaded portion is added to define the region corresponding to the (hopefully) unlikely case of operation in liquid water, and the data points indicate the monthly average conditions for a typical UK uncontrolled environment (i) when there is no internal heating, and (ii) when such heating is just sufficient to raise the temperature of the die by an amount (16 C) to ensure that the relative humidity at the die surface will always be less than 30%. From this data it can be concluded that a 1000 h 85°C/85% RH lifetest will simulate 20 years operation in any UK environment. However, by performing a similar exercise for tropical climates (typically 27°C/90% RH) it can be shown... 

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