| Period | 3 hours |
| Position | Dial up and pendant up |
| Temperature | - 20C and normal temperature |
| Permissable errors | 1 hour - 2 seconds
2 hours - 4 seconds 3 hours - 6 seconds |
Source: National Archives of Australia File A705, 150/4/1831, Instument
Instruction 8-1 Vol II