Using a Picoscope 7 Automotive Software
Frequency is the number of times per second an event occurs. In this case, the number of times the circuit is switched ON and OFF.
Frequency is measured in Hertz (hz)
The frequency can be fixed (as in this case) or variable.
Example of a Fixed Frequency Measurement
Automotive circuits that are rapidly cycled on and off by fast-acting electronics are said to be Pulse Width Modulated. (PWM) This accurate control method uses a fixed frequency variable Duty Cycle.
Example of Variable Frequency Measurement
Some sensors use a variable frequency output.
One such example is certain airmass meters.