Abstract: An enclosure method comprising a first enclosure portion and a second enclosure portion configured to mate with the first enclosure portion. A receptacle is provided on the first enclosure portion. The receptacle has a frangible wall portion accessible from an exterior of the first enclosure portion. The frangible wall portion is operable to be broken from outside the enclosure method. A protrusion is provided on the second enclosure portion and the protrusion is operable to be received in the receptacle. A first locking member is connected to the frangible wall portion to extend inside the receptacle and a second locking member is provided on the protrusion. The second locking member is configured to engage the first locking member such that separation of the first and second enclosure portions is prevented unless the frangible wall portion is deliberately broken.

Abstract: An enclosure method comprising a first enclosure portion and a second enclosure portion configured to mate with the first enclosure portion. A receptacle is provided on the first enclosure portion. The receptacle has a frangible wall portion accessible from an exterior of the first enclosure portion. The frangible wall portion is operable to be broken from outside the enclosure method. A protrusion is provided on the second enclosure portion and the protrusion is operable to be received in the receptacle. A first locking member is connected to the frangible wall portion to extend inside the receptacle and a second locking member is provided on the protrusion. The second locking member is configured to engage the first locking member such that separation of the first and second enclosure portions is prevented unless the frangible wall portion is deliberately broken.

Abstract: An enclosure apparatus comprising a first enclosure portion and a second enclosure portion configured to mate with the first enclosure portion. A receptacle is provided on the first enclosure portion. The receptacle has a frangible wall portion accessible from an exterior of the first enclosure portion. The frangible wall portion is operable to be broken from outside the enclosure apparatus. A protrusion is provided on the second enclosure portion and the protrusion is operable to be received in the receptacle. A first locking member is connected to the frangible wall portion to extend inside the receptacle and a second locking member is provided on the protrusion. The second locking member is configured to engage the first locking member such that separation of the first and second enclosure portions is prevented unless the frangible wall portion is deliberately broken.

Abstract: A method and apparatus for operating a monitoring unit operable to receive signals from a mobile transmitter in an electronic location monitoring system involves causing a first receiver to change a signal reception threshold thereof for receiving signals from the mobile transmitter, in response to proximity of the monitoring unit relative to a reference position whereby the receiver rejects signals received from the mobile transmitter that have a signal strength below the signal reception threshold and receives and processes signals received from the mobile transmitter that have a signal strength above the signal reception threshold. Alternatively, detection of a first monitoring unit in proximity to a second monitoring unit may cause the second monitoring unit to take over receiving signals from the mobile transmitter while the first monitoring unit is put into a low power mode.

Abstract: A simple, light weight air cooled filter arrangement for a high intensity narrow band pass filtered light fixture. In lighting fixtures such as infrared energy sources or stage lighting, it is necessary to filter a conventional broad spectrum energy source so that only energy in the desired region is transmitted. These filters which absorb energy in bands other than those being transmitted tend to become very hot particularly when high energy sources are required. A light fixture is provided having a plurality of spaced filters near a light output end. Each filter, except the outer most filter, has a portion of its outer periphery removed. These open areas are alternately positioned to form a tortuous air path between adjacent filters. A cooling fan draws filtered exterior ambient air through the tortuous paths between the filters and exits the warmed air past the energy source out the end remote from the filters.