87. 7 Thermodynamics of reversible cell 7.7.1. Measurement of Electromotive forces(emfs) (2) Weston standard cell The Weston cell, is a wet-chemical cell that produces a highly stable voltage suitable as a laboratory standard for calibration of voltmeters. Invented by Edward Weston in 1893,it was adopted as the international Standard for emf between 1911 and 1990(2) Weston standard cell The Weston cell, is a wet-chemical cell that produces a highly stable voltage suitable as a laboratory standard for calibration of voltmeters. Invented by Edward Weston in 1893, it was adopted as the International Standard for EMF between 1911 and 1990. 7.7.1. Measurement of Electromotive forces (emf's) §7.7 Thermodynamics of reversible cell