The Anonymous Widower

How To Build A Liverpool-Style Optical Bench

When I worked at ICI in Runcorn, one of the guys had developed a very accurate instrument for measuring trace chemicals in a dirty process stream. I remember one of these instruments was used to measure water in parts per million in methyl methaculate, which is the misnomer or base chemical for Perspex.

All the optical components needed to be mounted on a firm base, so a metre length of nine-inch C-section steel beam was chosen. The surface was then machined flat to a high accuracy.

In the end they found that instead of using new beams, old ones decades-old from the depths of a scrap yard gave better accuracy as the steel had all crystallised out. Machined and spray-painted no-one knew their history.

But they were superb instruments and ICI even sold them abroad.

October 14, 2021 - Posted by AnonW | World | Chemistry, Engineering, ICI, Perspex, Plastic, Runcorn, Steel