[Image: 1Lock-In Amplifier.jpg]
A lock-in amplifier (also known as a phase-sensitive detector) is a type of amplifier that can extract a signal with a known carrier wave from an extremely noisy environment (S/N ratio can be -60 dB or even lesscitation needed). It is essentially a homodyne with an extremely low pass filter (making it very narrow band). Lock-in amplifiers use mixing, through a frequency mixer, to convert the signal's phase and amplitude to a DC—actually DC--actually a time-varying low-frequency—voltage frequency--voltage signal.
The device is often used to measure phase shift, even when the signals are large and of high signal-to-noise ratio, and do not need further improvement.
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The lock-in amplifier was invented by Princeton University physicist Robert H. Dicke who founded the company Princeton Applied Research (PAR) to market the product.http://en.wikipedia.org/wiki/Lock-in_amplifier
This model is: ''SR830 Dual Phase Lock-In Amplifier''
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Current Location: 36-228
Vendor: http://www.thinksrs.com/index.htm Stanford Research Systems, Inc.
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