Lock in amplifier

1. What does a lock-in amplifier do?
2. How does a lock-in work?
3. What is the purpose for dual phase lock-in amplifier?
4. How does a phase sensitive detector work?

What does a lock-in amplifier do?

Lock-in amplifiers are used to detect and measure very small AC signalsall the way down to a few nanovolts. Accurate measurements may be made even when the small signal is obscured by noise sources many thousands of times larger.

How does a lock-in work?

Lock-in parties are parties where individuals can enter and leave at a specified time. For example, if the party starts at 5:30 or 6:00 PM, it will end at 10:00 or 11:00 AM. Whatever it is, a lock-in party must begin early and have a sleepover.

What is the purpose for dual phase lock-in amplifier?

A complete digital dual-phase lock-in amplifier system based on DSP and LabVIEW was designed. It can extract the weak sinusoidal signals submerged by noise. This design has the advantages of high accuracy, low cost and portability, and its update and transplantation are easy.

How does a phase sensitive detector work?

A lock-in, or phase-sensitive, amplifier is simply a fancy AC voltmeter. Along with the input, one supplies it with a periodic reference signal. The amplifier then responds only to the portion of the input signal that occurs at the reference frequency with a fixed phase relationship.