Two similarly dimensioned cases are preferably placed one on top of the other, with air space and electrical connections between them. The upper case has a door with a window and contains a slide-out and swing-out frame holding the indicating instrument and PC boards. The power supply is on the rear...http://www.google.fr/patents/US4287764?utm_source=gb-gplus-shareBrevet US4287764 - Fluid analyzer construction and housing
