Lock-In Amplifiers recover signals in the midst of overwhelming noise environments. Alternative uses include providing higher resolution measurements of relatively clean signals over several orders of magnitude and frequency, or even measuring noise itself. Common applications include as precision AC voltage and AC phase meters, noise measurement units, network analyzers, spectrum analyzers and phase detectors.
Rent a lock-in amplifier when you need to detect and measure microscopic AC signals all the way down to a few nanovolts. Lock-in amplifiers use a technique known as phase-sensitive detection. This singles out components of the signal at a specifically referenced frequency and phase-- meaning accurate measurements can be taken even when tiny signals are obscured by noise sources many thousands of times larger. Noise signals at non-specified frequencies are rejected and do not affect measurement. The best instruments on the market today have a dynamic reserve of over 100 dB, indicating they are capable of accurately measuring a signal in the presence of noise up to a million times higher in amplitude than the signal of interest.