G6B/140 - Watches Stop Mk. V B (Split Second graduated to 360 degrees for direction finding)
Tests
Period
3 hour in each position and temperature
Position
Dial up and pendant up
Temperature
-20C and normal
Permissable errors
1 hour - 4seconds
3 hours - 10 seconds
plus 50% at -20C
Source: A705, 150/4/1831