Single pan substitution analytical balance, Oertling type R.20, serial no. 11332, made 1964, capacity 200 gms. Features pre-weighing facility, glazed, bronze coloured, metal and plastic case.

Modern single pan analytical balance made by L. Oertling Ltd, London England. The type R.20 scales are capable of weighing to a hundredth of a gram using a system of substitute weights that are placed at the other end of the balance beam. These are moved by the use of rods and levers operated by a series of rotary knobs. The weight is indicated by the values of the various knobs when the beam is balanced as shown by a circle of light projected onto an etched glass reticule at the front.