The G1/236G is a cold cathode gas filled relay originally designed for use in telephone systems and with possible applications in counting equipment.
The central trigger lead needs to be connected to a high impedance source. Typically 1 MΩ.
When triggered the anode current of this cold cathode device should lie between 0.5 and 1.5 mA. The anode supply would be of the order of 175 Volts. When conducting the anode volts would be between 70 and 85 Volts.
The reverse shows the CV3524 designation.
The main electrodes are the ring and the short rod. The trigger is a spiral wire connected to the centre electrode and comes vert close to the ring electrode.
The thin glass tube envelope is 8 mm in diameter and, excluding the 3 wire leads is 38 mm tall.
Reference: 1040. Type G1/236G was first introduced in 1955.