Lock-In Amplifiers

Lock-in amplifiers are used to measure the amplitude and phase of repetitive AC signals buried in noise. They achieve this by acting as a narrow bandpass filter which removes unwanted noise while allowing through the signal which is to be measured. The AC frequency of the signal to be measured is used as a reference signal to set the passband region of the filter, and must be supplied to the lock-in amplifier along with the unknown signal.

• What is a Lock-In Amplifier? A quick overview of what lock-in amplifiers do for you
• Noise in Lock-Ins  A note on interpretation of noise input figures
• What Are Lock-In Amplifiers? Scitec Instruments's listing of helpful sites

• Scitec Model 410 Single Phase Lock-in Amplifier
• Scitec Model 420 Dual Phase Lock-in Amplifier
• Scitec Model 430 Board-Level Single Phase Lock-in Amplifier
• Scitec Model 441 Board-Level Dual Phase Lock-in Amplifier
• Becker & Hickl LIM-100 Single Phase Lock-in Amplifier

• Scitec Model 410 manual
• Scitec Model 420 manual
• Scitec Model 430 and 441 manual

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