3. Minute Recording Chronograph Chronograph Functions index
Timing to 1/5 second [C].
Timing
up to 30 minutes [D].
Timing telephone conversations [E].
The dial of the chronograph No. 3 is calibrated for timing 1/5 second.
Timing up to 30 minutes, or in some cases 45 minutes, is possible with a minute-recording chronograph. For each rotation of the chronograph hand the minute-recording hand moves one division. Both hands return to zero simultaneously.
Charges for telephone calls are usually based on periods of 3 minutes; the special 3rd, 6th and 9th-minute divisions show at a glance the number of three-minute periods that have elapsed. (Note this was prevalent in the 1950's to the 1980's)
C = 1/5 second divisions
D = Minute recorder
E = Three minute divisions for telephone calls