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Typically, these fences are 2.4 metres (7 ft 10 in) tall and send high voltage electric pulses through the palisade at a frequency of 1 Hz (one pulse per second). Palisade electric fences are used in most countries, particularly where there is little vegetation to short-circuit the fence or where the costs of security personnel are high in ...
A pet fence or radio fence, is an electronic system designed to keep a pet or other domestic animal within a set of predefined boundaries without the use of a physical barrier. A mild electric shock is delivered by an electronic collar if its warning sound is ignored.
A frequency counter is an electronic instrument, or component of one, that is used for measuring frequency. Frequency counters usually measure the number of cycles of oscillation or pulses per second in a periodic electronic signal. Such an instrument is sometimes called a cymometer, particularly one of Chinese manufacture. [citation needed]
Invisible Fence Inc. (commonly referred to as Invisible Fence Brand) is a company that designs radio pet fences for cats and dogs. Manufactured and distributed by Radio System Corporation, the company sells wireless and fenceless systems that were first introduced in 1973. [ 1 ]
To start the identification procedure, the ground operator switched the pulse frequency of his radar from 3,750 Hz to 5,000 Hz. The airborne receiver decoded that and started to transmit the day code. The radar operator would then see the blip lengthen and shorten in the given code.
Pulse generators may use digital techniques, analog techniques, or a combination of both techniques to form the output pulses. For example, the pulse repetition rate and duration may be digitally controlled but the pulse amplitude and rise and fall times may be determined by analog circuitry in the output stage of the pulse generator.
Residents near a Cold War-era nuclear bomb shelter are wondering what the property's new owners are doing on the other side of the chain-link fence topped by barbed wire.
A procedure for ultrasonic testing is outlined in ASTM C597 - 09. [9]In India, till 2018 ultrasonic testing was conducted according to IS 13311-1992.From 2018, procedure and specification for Ultrasonic pulse velocity test is outlined in IS 516 Part 5:Non destructive testing of concrete Section 1:Ultrasonic Pulse Velocity Testing.