Abstract: The trailer including a main towing device movable by articulation and sliding, from top to bottom, from front to rear and from right to left to facilitate hitching the trailer to the back of a motor vehicle using a conventional ball-type trailer hitch in conformity with international road regulations. The towing device includes a flexible fixing device to fasten the front part of the trailer to the roof of the motor vehicle through a transverse and vertical centering device which slides from front to rear through sliding rails mounted on a roof-rack, or, as an alternative, through sliding rails mounted underneath the front part of the trailer. The combination of the devices enables rapid coupling and uncoupling of the trailer and the motor vehicle, the locking of the sliding motion of the main towing device in road-ready position being automatically performed by means of locks.

Abstract: A device for demonstrating the operation of gas contaminant testing apparatus and for training persons to use such apparatus. The device can be portable and allows demonstration of and training on testing apparatus in a location removed from the environment in which the gaseous medium and its gaseous and vaporous contaminants are normally found. The device uses very small contaminant samples for demonstration in order to minimize personnel exposure and inadvertent or deliberate releases to the environment. The device allows the substitutions of, for training and demonstration purposes, a harmless gaseous medium for the actual gaseous medium of interest. In a preferred embodiment, designed for demonstrating the operation of a refrigerant contaminant testing apparatus, air is susbstituted for refrigerant as the gaseous medium in which contaminants are entrained when using the device. In that embodiment, air is caused to flow through a container holding a contaminant sample of interest.