Improving student understanding of lock-in amplifiers

DeVore, Seth; Gauthier, Alexandre; Levy, Jeremy; Singh, Chandralekha

doi:10.1119/1.4934957

Cited by 19 publications

(10 citation statements)

References 16 publications

(13 reference statements)

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“…We have shown how the algorithm of lock-in feedback amplifiers, which is routinely used in high-precision physics experiments [ 38 ], can be applied to social science experiments. In this setting the algorithm allows experimenters to optimally choose treatment values in a multidimensional treatment space even in the face of large noise.…”

Section: Discussionmentioning

confidence: 99%

Uncovering noisy social signals: Using optimization methods from experimental physics to study social phenomena

2017

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Due to the ubiquitous presence of treatment heterogeneity, measurement error, and contextual confounders, numerous social phenomena are hard to study. Precise control of treatment variables and possible confounders is often key to the success of studies in the social sciences, yet often proves out of the realm of control of the experimenter. To amend this situation we propose a novel approach coined “lock-in feedback” which is based on a method that is routinely used in high-precision physics experiments to extract small signals out of a noisy environment. Here, we adapt the method to noisy social signals in multiple dimensions and evaluate it by studying an inherently noisy topic: the perception of (subjective) beauty. We show that the lock-in feedback approach allows one to select optimal treatment levels despite the presence of considerable noise. Furthermore, through the introduction of an external contextual shock we demonstrate that we can find relationships between noisy variables that were hitherto unknown. We therefore argue that lock-in methods may provide a valuable addition to the social scientist’s experimental toolbox and we explicitly discuss a number of future applications.

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Section: Discussionmentioning

confidence: 99%

Uncovering noisy social signals: Using optimization methods from experimental physics to study social phenomena

2017

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“…The frequency ω m of the modulation has to be slow enough that the magnetization does not deviate significantly from its steady state, which means that ω m < Γ. The derivative of the Lorentzian is generated when the signal from the photodiode is demodulated using a lock-in amplifier [137]. Internally, the lock-in determines the amplitude of the signal component at a given reference frequency, which should be the same as ω m .…”

Section: Choose Your Components and Assemble Your Magnetometermentioning

confidence: 99%

How to build a magnetometer with thermal atomic vapors: A tutorial

Fabricant¹,

Novikova²,

Bison³

2022

Preprint

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This manuscript is designed as a step-by-step guide to optically pumped magnetometers based on alkali atomic vapor cells. We begin with a general introduction to atomic magneto-optical response, as well as expected magnetometer performance merits and how they are affected by main sources of noise. This is followed by a brief comparison of different magnetometer realizations and an overview of current research, with the aim of helping readers to identify the most suitable magnetometer type for specific applications. Next, we discuss some practical considerations for experimental implementations, using the case of an M z magnetometer as an example of the design process. Finally, an interactive workbook with real magnetometer data is provided to illustrate magnetometer-performance analysis.

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“…Students with such backgrounds can develop and apply their knowledge to potentiostats for electrochemistry, , characterization of microelectrodes, measurement of pH, peak resolution, and photometry . Lock-in amplifiers (LIAs) are commonly used in research laboratories to improve signal-to-noise and to analyze time-dependent responses, and their construction provides a particularly good exercise for teaching undergraduate students about circuit principles and applications. − Previously reported LIA designs use prepackaged LIA integrated circuits such as ADA2200, which enable efficient construction but provide less opportunity for learning, or they use chips such as AD630, which provide a more open architecture but do not provide a means for measuring phase shifts that are critical in understanding time-dependent drive-response behavior (e.g., alternating current or AC circuits).…”

Section: Introductionmentioning

confidence: 99%

Low-Cost, High-Performance Lock-in Amplifier for Pedagogical and Practical Applications

Suganuma

Dhirani

2020

J. Chem. Educ.

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Lock-in amplifiers (LIAs) are commonly used in chemistry laboratories to improve noise-to-signal ratios. Constructing and testing a suitably designed LIA provide undergraduate students with an excellent opportunity to learn about theory, construction, and applications of LIA. In particular, students can learn about time-dependent behavior and various components, from resistors (R) and capacitors (C) to packaged microchips such as demodulators and phase shifters. We provide here design and performance characteristics of a two-(Vx, Vy) channel LIA based on balanced modulator/demodulators (AD630). The LIA includes configurable resistor−capacitor (RC) high-pass and low-pass filters, various op-amp circuits, and a phase-shifter. Various configurations of resistors/capacitors, as well as salt solutions and isopropanol/pentane mixtures, are used as samples to measure conductance or capacitance to test both V x and V y channels of the LIA. The results are consistent with behaviors expected theoretically. The LIAs yield excellent noise/signal ratios with peak-to-peak values that are <0.2% and that compare favorably with commercial LIA performance.

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Improving student understanding of lock-in amplifiers

Cited by 19 publications

References 16 publications

Uncovering noisy social signals: Using optimization methods from experimental physics to study social phenomena

Uncovering noisy social signals: Using optimization methods from experimental physics to study social phenomena

How to build a magnetometer with thermal atomic vapors: A tutorial

Low-Cost, High-Performance Lock-in Amplifier for Pedagogical and Practical Applications

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