Chamber Loadings

National Surveys. New England Journal of Medicine, vol. 339, 1998, pp. 813-818. Reports surveys showing high public support for requiring various gun safety devices including support for childproofing (88 percent), personalization (71 percent), magazine safeties (82 percent), and loaded chamber indicators (73 percent). 

Vernick, J. S., et al. Unintentional and Undetermined Firearm-Related Deaths A Preventable Death Analysis for Three Safety Devices. Injury Prevention, vol. 9, 2003, pp. 307-11. Concludes that 44 percent of the deaths studied could have been prevented if the gun in question had at least one of the following safety devices personalization, loaded-chamber indicator, or magazine safety. 

Prior to initiating loaded chamber heat penetration studies, a container mapping study should be conducted. The intent of this study is to determine the coolest point within a liquid-filled container. 

In subsequent loaded chamber heat penetration studies, penetration thermocouples should be positioned within the container at the previously determined cold spot. The temperature profile of the container should remain constant among different sterilizing chambers, utilizing steam heat as the sterilizing medium. 

The intent of this study is to demonstrate the temperature uniformity and stability of the sterilizing medium throughout the sterilizer. Temperature distribution studies should be conducted on both empty and loaded chambers with maximum and minimum load configurations. Temperature uniformity may be influenced by the type, size, design, and installation of the sterilizer. The manufacturer of the vessel, based on the variables mentioned, should determine a satisfactory empty chamber temperature uniformity. 

The number of thermocouples utilized in the heat distribution study will be dependent on sterilizer size. In a production-size sterilizer, 15 to 20 thermocouples should be adequate. The thermocouples utilized for loaded chamber heat distribution studies should be positioned in the same locations used for empty chamber heat distribution studies. The... 

Loaded Chamber Heat Penetration Study — Load Cool Point... 

The temperature and/or humidity mapping study for the PQ test is performed upon successful completion of the OQ test. It is similar to the OQ test however, the test is performed under fully loaded conditions. The load in this case consists of empty containers used to simulate a fully loaded chamber. This would simulate a worst-case scenario where the chamber is fully loaded with product... 

Maximum chamber vacuum under no load Chamber leak rates under vacuum and pressure Shelf temperature control (i.e., temperature variation)... 

A leak rate of 0.8-0.9 mbar L/s is already larger than could be pumped off by a reasonable pumpset in this size of freezedrying plant. The partial pressure of air, p.m, must be small compared with the water vapor pressure. At 0.28 mbar total pressure pair should be 0.03-0.04 mbar. A vacuum pump which can pump 0.8-0.9 mbar L/s at 0.03-0.04 mbar must have a pumping speed of -100 m3/h, which is unusually large for a 200 L chamber. A vacuum pump with a 40 m3/h pumping speed will theoretically evacuate a chamber and condenser (total 500 L) in -6 min down to 0.1 mbar. Even if it takes 10 min with the loaded chamber, the pumping speed of the pump is sufficient. With this pump, the leak rate of the plant should not exceed 0.4 mbar L/s, which would be pumped at -0.04 mbar. 

Loading density is a very important parameter, both in propellant powders (owing to the necessity of ensuring the strongest possible propellant effect in the loaded chamber, whose shape and size are mostly limited by the design of the weapon) and in brisant explosives (- Brisance). 

The results of the study are summarized in Table III which provides 2-hour desiccator values and dynamic chamber values for both fresh and aired out panels. For most of the product types, both empty chamber and loaded chamber formaldehyde values are provided, the empty chamber values representing background measurements taken just before the chamber was loaded. These background levels represent residual formaldehyde present in the chamber from previous testing. 

The data indicate that the loaded chamber values were below 0.1 ppm for all products and, also, that the background levels (in the empty chamber) were on the same order of magnitude as the levels observed with panels present. In fact, the data show that the background levels in some cases were as high as the levels measured when the chamber was fully loaded, especially after the panels had been... 

Table X. Two Product Loading Chamber Formaldehyde Levels...

Table XIV. Three Product Loading Chamber Combination...

Perform three (3) loaded chamber heat penetration studies to determine the coolest point within a specified load and configuration. A Kaye Validator equipped with thermocouple-probed containers will be used to provide an equal representation among layers in the chamber. 

Chemical munitions are placed in a cardboard box or carrier, which is transported to the top of the kiln. The boxed munitions are fed into the kiln through two loading chambers, each having its own door. The boxed munitions are dropped onto a heated (500°C-550°C) shrapnel (scrap) bed at the bottom of the detonation chamber. If sufficient energy from energetics in the munition is released, no additional external heating from the electrical resistance elements is required. If the munition does not contain energetics, additional heat can be provided by the electrical resistance elements. 

The technology vendor states that boxed munitions can be removed at any time from the loading chambers and that once in the detonation chamber, sufficient residual heat remains to destroy the munition, even if there is no external energy (i.e., electricity for the resistance heaters) to further heat the chamber. 

The loading chamber is similar to the low-gravity chamber we described in detail previously (Tulp et al., 1980a). In Figure 10a the loading... 

A piece of ordnance having a number of load-chambers attached to a vertiual axis, and consecutively presented at the rear of a cannon-bore. As each takes its place at the breech, it is advanced into the bore and locked before firing. (Haisuy, 1862 Dodge, 1856.)... 

The first stage in a high-vacuum cycle is to evacuate the loaded chamber. Some cycles may require a single evacuation, others may require a pulsing cycle of evacuation followed by steam injection repeated several times. The nature of the load dictates the cycle. Evacuation may be controlled through a pressure switch or transducer or simply by a timer governing pump running time. It is usual to find a condenser positioned between the chamber and the pump for purposes of pump protection. 

Each heat sterilization cycle should be recorded by appropriate equipment with suitable accuracy and predsion, e.g., on a time/temperature chart with a suitably large scale. The temperature should be recorded from a probe at the coolest part of the load or loaded chamber, this point having been determined during the validation the temperature should preferably be checked against a second independent temperature probe located at the same position. The chart, or a photocopy of it, should form part of the batch record. Chemical or biological indicators may also be used but should not take the place of physical controls. 

A temperature sensing probe for the automatic temperature recorder should be located at the position in the steriliser shown, by previous studies, to be in the coolest part of the loaded chamber. 

Each cycle of heat sterilisation should be monitored with suitable temperature sensing probe(s) located at the coolest part(s) of the loaded chamber, as determined by the studies described under Validation, or at a location bearing a known relation to the coolest part... 

Where sterilising conditions are less stringent than 121°C/15 min (or a delivered F0 of 8 measured by integrated heat exposure) for moist heat or 160°C/2 hours (or equivalent) for dry heat additional temperature sensing probes should be employed in simulated product packs throughout the loaded chamber or another acceptable monitoring system utilised. 

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