Electronic Instruments Ltd. Portable pH Meter, Model 30, Richmond, Surrey, England. A laboratory instrument designed for the measurement of acidity and alkalinity (pH) in chemical, biological, and industrial samples. The unit features a large analogue meter calibrated for pH and millivolt readings, with controls for temperature compensation, buffer calibration, and zero adjustment. The instrument would originally have been used with a glass electrode and reference electrode mounted in the storage compartment within the case lid. Used in universities, water analysis, brewing, and chemical laboratories. c.1940s–1950s.
W36 x D17 x H29 cm.
Untested.
