Ultrasonic waves are sound waves transmitted above the human-detectable frequency range, usually above 20,000 Hz. They are used by some animals and in medical or industrial technological devices. More »

Ultrasonic devices do nothing to repel or kill pests such as mosquitoes, according to the University of Florida's Institute of Food and Agricultural Sciences. The devices do not help to protect humans or animals from dis... More »

www.reference.com Home & Garden Pest Control

The BugzOff Electronic Pest Repeller, T3-R Triple High Impact Mice, Rat, Rodent Repeller and the Riddex Plus Plug & Go Pest Repeller System are highly-rated electronic ultrasonic pest control devices. As of 2015, these a... More »

www.reference.com Home & Garden Pest Control

Ultrasonic sound waves are waves of sound beyond the range of perception. These sound waves are used by bats and dolphins for navigation and by medical imaging and in non-destructive testing. More »

www.reference.com Science Physics Optics & Waves

All ultrasonic waves share the common property of being mechanical waves with a frequency higher than the upper limit of the human hearing range. The only difference in physical properties between ultrasonic and sub-ultr... More »

www.reference.com Science Physics Optics & Waves

The frequency range of ultraviolet waves is between 7.5 x 10^14 and 3 x 10^16 Hertz. For this range, the corresponding ultraviolet light wavelengths are 400 to 10 nanometers. Ultraviolet light waves are below the visible... More »

According to Britannica, hertz are units of frequency, so 50 Hz contains less frequency than 60 Hz. These units are used to calculate electric currents, electromagnetic waves and sound. More »