Abstract: 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 wall. The lower case has a slide-out tray, a door is hinged on the front edge, and on a horizontal axis. The tray supports the analyzer proper with incorporated preamplifiers. Both doors have sealing strips on the inside and can be bolted.

Abstract: An analyzer such as a two beam infrared analyzer is assembled in building block fashion and includes a radiation source module and a detection module tied together by rods and in optical alignment with each other. Intermediate or "cell"-modules are hung on the rods and all adjacent, interfacing faces of the several modules are constructed for indexing, preventing lateral deflection when the fastened rods hold all parts together.

Abstract: A two beam radiation detector has two gas systems in a metal block. Each system has two detection chambers, one per incident radiation beam, and two chambers, pertaining to different systems, are traversed by the same beam. The two systems further include a common, but biparted, pressure difference sensing chamber containing a flexible membrane.

Abstract: A cylindrical block is provided with two ducts, forming a V whose legs terminate in exit windows in one axial end face of the block. A light source is disposed in the bottom of the V to direct light into both ducts. The block is further traversed by a bore, terminating as to one end in between the windows, avoiding the ducts and terminating in an offset position relative to the V-bottom and the light source at the other end of the block. A shaft traverses this bore for rotating a shutter in front of the windows. A complementary, light receiving unit is disposed with misaligned entrance windows in front of the unit windows, but their centers are traversed respectively by the optical axes of the ducts.