lock-in amplifier


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lock-in amplifier

[′läk‚in ′am·plə‚fī·ər]
(electronics)
An amplifier that uses some form of automatic synchronization with an external reference signal to detect and measure very weak electromagnetic radiation at radio or optical wavelengths in the presence of very high noise levels.
References in periodicals archive ?
It comes with the vendor's cryogen-free bottom-loading cryostat (the OptistatDry BLV), an MFLI lock-in amplifier from Zurich Instruments, a specially designed ESD break-out box, and high-quality cables.
Low Resistance set-up for use with Lock-in amplifier 46.
Either the phase or the dispersive in-phase output of the lock-in amplifier can be used in a feedback loop to lock the driving frequency to the Larmor frequency by stabilizing the phase shift to -90[degrees].
The block diagram of a typical lock-in amplifier is shown in Figure 2.
The lock-in amplifier uses this reference signal to select a small range of signal frequencies centered on the reference frequency to amplify and deliver to the signal measuring circuit.
A lock-in amplifier with two detectors--a dual-phase lock-in--has two references in quadrature and determines both the cosine of the phase difference as well as a separate sine term.
In theory, a lock-in amplifier seems like a great idea.
The PMD resolution of the system appears to be limited by the phase noise of the lock-in amplifier itself.
In spite of the high performance lock-in amplifier used as a second stage signal-amplifier, the signal-to-noise ratio must be optimized for the output of the photocurrent measuring preamplifier.
The output signal maximum of 1 V is determined by the largest full-scale signal of the lock-in amplifier input where the output signal is connected.
Typical applications include spectroscopy, particle detection, fast current and resistance measurements, general lab use and front end for ultrafast lock-in amplifiers, oscilloscopes and A/D converters.