For use as a light operated timing gate (IPC-3210-T). Comprises photodetector and light source each housed in a robust ABS case spaced 40mm apart on a plastic rod. Light source housing has battery compartment and on/off switch. Photodetector housing is fitted with a pair of 4mm sockets to allow connection to electronic timers. When the timing gate is switched on it creates a short circuit between the two output sockets, this then becomes an open circuit each time the light beam is interrupted. Consequently the timing gate can be used as a remote switching device in a wide range of dynamics experiments.
A document containing descriptions and diagrams of how to set up the ‘g’ by freefall experiment using the Photo Timing Gate with either the Millisecond Timer (IPC-3834-T) or the Timer Scaler & Frequency Meter (IPC-3342-T) has been compiled by us.