In general small analytes have megahertz frequencies while larger analytes can be only a few hundred hertz.
The rate at which the air pressure oscillates is the frequency of the tone, which is measured in oscillations per second, called hertz.
When variable "x" has units of seconds, "f" has units of hertz.
The audible range of sound is 20 hertz-20 kilohertz.
The signal falls off exponentially as a function of frequency, so frequencies around 1-10 hertz are frequently used.
A 1200 hertz amplitude modulated sine wave is pressed into the left and right channels with a phase difference of 90 degrees.
The transducers were temporarily altered for this test to transmit sound at 50 hertz, which is lower than their normal operating frequency.
Since the numerator is usually in hertz, and the denominator in megahertz, delta is expressed in ppm.
