ID: 
32
Maker's Name: 
Weston
Where made: 
USA
Dimensions: 
12.5 × 8.8 × 11.5 cm

Cadmium Amalgam and Mercury in a saturated solution of Cadmium Sulphate make a cell of reasonably constant voltage, hence used as a standard of EMF in bridges. Initial voltage around 1.018636 Volts. Discarded when voltage drops below 1.0183 Volts. Well-made cells agree within microVolts and should be checked annually against a known stable cell.