Traffic Tally 21

The TT-21 has been replaced with the TT-51

Lightweight Single Inductive Loop Accumulator- Discontinued

The Traffic Tally 21 is a solid-state inductive loop detector counter for use with loops buried under the roadway. The counter will operate under all field conditions for over one year, on one set of batteries.

The TT-21 is a volume counter that holds one continuous count (accumulator), designed to give the user the ability to adjust the time delay.

To enable a counter to register one count per vehicle, a time delay feature is needed. A properly set time delay will eliminate multiple counts from trucks and trailers and still count a vehicle close behind.