Collection of instruments (pH meters etc) made by Electronic Instruments Ltd (E.I.L) 1946-1965 (60 items) Collection of instruments made by Electronic Instruments Ltd 1946-1965
pH meter type D-303-B with spare dip electrode made by Muirhead and Co. Ltd., Beckenham, Kent, 1940-1950 pH meter type D-303-B with spare dip electrode made by Muirhead and Co. Ltd. 1940-1950
Model 23A Direct reading pH meter used to monitor the pH of media -in organ or tissue culture at the Common Cold Research Unit, 1961-1980 Model 23A Direct reading pH meter used to monitor the pH of media
Hand-held pH meter, ion selective field effect transistor (ISFET) type, model KS501, with sales leaflet, by Camlab Limited, Cambridge, England, 1997. Portable Camlab pH Meter, 1997 1997
Pye "Dynocap", pH meter-millivoltmeter with accessories, by Pye Unicam, Cambridge, 1960-1962 Pye "Dynocap"
pH meter type D-449-A, no. 152936, by Muirhead and Co. Ltd., patent 581270, February 1948, with electrodes and tray pH meter type D-449-A, with electrodes and tray 1948
PH meter, type TF 717 A/M made by Marconi Instruments Ltd., (serial no 7234 184), mains operated, c. 1950 PH meter 1950
Pye-Unicam 292 MKII pH meter with attached Electrode, Serial No. 114565. Pye-Unicam 292 MKII pH meter with attached Electrode
pH meter, in mahogany case BY Doran Instrument Co. Ltd., Stroud, Glos., England, 1957. British patent no.593920 pH meter 1957
Portable pH meter with accessories, ion selective electrode (ISE type), for fluoride measurement, by the Hach company, c. 1990. Model no.45400, serial no. 921000000784. Portable pH Meter, 1985-1995 1985-1995