Object StatementPortable pH meter, with batteries (5), used in the baking operation of manufactured biscuits, wood / metal / paper / glass, made by N. L. Jones, Sandringham, Victoria, Australia, 1952-1957, used by George Weston Foods Ltd, Biscuit and Cake Division, Camperdown, New South Wales, Australia, 1952-1980
Physical DescriptionThe meter was used to measure pH during baking of biscuits at George Weston Foods Ltd, Biscuit and Cake Division in Camperdown, New South Wales. The meter is contained in a portable wooden box; it is a Model B pH electrometer which uses a simple null detector method, which is one of the earliest forms of electronic pH detection methods. There are printed instructions attached to the inside of the lid, black coloured controls on top of the box, direct read-out of pH on small scale marked 1-14. It is powered by a Weston (note: no relation to George Weston) standard cell (inside the box) and has a separate pH electrode and a reference calomel electrode mounted on a small hinged door in the front of the box. Electrical leads from the electrodes are plugged into sockets on the box within the electrode cabinet. The electrode cabinet is lined with metal to form an electrostatic shield.
MarksInstructions for use are attached to the inside of the lid.Handwritten at the top of the instructions, 'New Cells 8-7-63 (illeg.) / 9-6-65', and at the lower right corner, 'KCI Xtals'.
Inscribed 'MODEL B pH ELECTROMETER / N. L . Jones MELBOURNE' on top of unit at middle centre.
On rims at base of electrical cords within small hinged door, printed 'JONES MELB CAT. NO. 300' on one and 'JONES TYPE A CAT. NO. 100' on the other.