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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 less). 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 a time-varying low-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.

Recovering signals at low signal-to-noise ratios requires a strong, clean reference signal the same frequency as the received signal. This is not the case in many experiments, so the instrument can recover signals buried in the noise only in a limited set of circumstances.

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


Current Location: 36-228

Vendor: Stanford Research Systems

Manual: Instruction Manual

Specifications: Datasheet

LabView Programs: Available

Price: $4500

Purchase Date: 10-3-2008