A little piece of history was made recently, when the Science Museum formally took possession of an original ‘Joyce-Loebl Microdensitometer Mark 4’ from the LMB. This equipment was designed in the 1970s, with significant input from the LMB’s Electronics and Technical Instrumentation Workshops, as a precision scanning instrument to measure and record spatially resolved optical density in photographic film. Developed and updated until the 2000s, the microdensitometer has only relatively recently been superseded by newer technology. This photo for day 27 of #LMB365 shows the handover of the electronic control unit to the Science Museum by Richard Henderson.