Gasometric coulometers (Hydrogen-oxygen coulometers):

Hydrogen-oxygen coulometer consists of a glass tube of about 50 cm long and a diameter of 2 cm.  There are two platinum sheets of about l.5 sq.cm are joined along with a stout platinum wire serve as the electrodes. A calibrated tube (gas burette) is linked to the electrolysis tube through means of a pressure rubber tube and is capable of moving vertically so as to adjust the pressure of the collected gases to atmospheric pressure before measuring the volumes of gases. A 0.5 M solution of potassium sulphate is used as the electrolyte.

Figure: Hydrogen oxygen coulometer