A Rotary Pulse Indicator for high-speed measurements is available.
There are 4 products of Pulse Input.
Digital Rotary Pulse Meter Capable of 50 kHz Measurements
Digital Time Interval Meter for Measuring Passing Speed, Time, or Cycle between Two Points.
Measure High-speed Up/down Pulses with this Up/down Pulse Meter.
Highly Visible LCD Display with 2-color (Red and Green) LEDs