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The National MagLab is funded by the National Science Foundation and the State of Florida.

Oscilloscope – 1897

From the auto shop to the doctor's office, the oscilloscope is an important diagnostic tool.

Oscilloscope – 1897

Indispensable in workplaces from medical offices to electronics repair shops to physics labs, the oscilloscope is a versatile and widely used diagnostic instrument. A mechanic may use an oscilloscope to measure engine function, while a medical researcher uses it to monitor heart activity.

An oscilloscope works by interpreting changes in a fluctuating electrical impulse and depicting them in waveform on the monitor of a cathode ray tube. That screen utilizes a moving dot to show the vertical and horizontal response to the variations of the signal. In situations where it is important to note the precise wave shape of an electrical signal, oscilloscopes are usually the tool of choice. Besides measuring the maximum variation of a signal, an oscilloscope can indicate the distortion and frequency of multiple related signals.

One of the most frequent applications involves troubleshooting faulty electronic equipment; the oscilloscope has the benefit of showing signals to help pinpoint the source of a problem. Whereas a voltmeter may indicate a highly unusual reading, an oscilloscope may show more specific information, such as whether the circuit is oscillating. Checking new circuitry is another common usage, as it is not unusual for fresh circuits to malfunction as the result of faulty voltage levels or design mistakes.

André-Eugène Blondel, a French engineer and physicist, is credited with inventing the oscilloscope during the latter portion of the 19th century. Early in his career, his legs became paralyzed but he never stopped working. Over the years, the design by Blondel evolved with developments in technology, one of which came during the high-tech era. The analog oscilloscope attaches the voltage level being quantified to the electron ray in motion on the screen. The current redirects the beam vertically and horizontally, providing a prompt view of the waveform. A digital oscilloscope changes the voltage being measured into discrete binary numbers and then uses this digital information to reconstruct the wave.

Handheld oscilloscopes, once derided as inferior to the larger models, now offer comparable levels of service, while offering the added advantage of portability. These smaller versions are becoming increasingly popular for hobby and automotive uses. Most contain features allowing fast and easy on-the-spot measurements.