Quick Answer:The Stop Clock is a spring-wound mechanical timer with a large 60-second dial and a small 30-minute dial, read to 1 s on the standard model. It needs no batteries and has top-mounted start/stop and reset buttons.
Last updated: 18 October 2026
Key Features
Spring-wound movement; no batteries required.
Large 60 s outer dial and small 30 min inner dial.
Least count of 1 s on the standard model.
Start/stop and reset buttons on top.
Black markings on a white face; wide base with non-slip feet.
Technical Specifications
Specification
Value
Movement
Spring-wound mechanical
Dials
60 s outer, 30 min inner
Least count
1 s (standard)
Controls
Top-mounted start/stop and reset
Dial face
Black markings on white
Base
Wide, non-slip feet
How It Is Used
After winding, the clock is started at the beginning of an event and stopped at its end; seconds are read on the large dial and minutes on the small one before resetting. It is used for timing pendulum oscillations, motion experiments and chemical reaction rates.
Frequently Asked Questions
Does the Stop Clock need a battery?
No. It has a spring-wound mechanical movement.
How long can the Stop Clock time?
The small inner dial counts up to 30 minutes, with seconds read on the 60-second outer dial.
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