# Low-cost ultrasonic distance measurement in a mechanical resonance experiment

## TL;DR

This paper introduces a low-cost ultrasonic sensor system for measuring mechanical resonance in lab courses, enabling students to efficiently collect data on amplitude and phase lag across frequencies.

## Contribution

It presents a novel, affordable dual-probe ultrasonic measurement setup with real-time data processing suitable for educational settings.

## Key findings

- Successful implementation of ultrasonic sensors for resonance measurement
- Effective lag compensation using a modified Savitzky-Golay filter
- Facilitates large-scale, hands-on physics experiments in educational labs

## Abstract

We present a low-cost, dual-probe position sensor in a mechanical resonance experiment suitable for deployment in large lab courses with multiple stations. The motion of the two ends of a driven, damped spring oscillator is recorded with US-100 ultrasonic distance sensors and ESP8266 microcontrollers. Sensor lag is compensated via a modified Savitzky-Golay filter. Data is downloaded to a computer via Wi-Fi in a format suitable for analysis in Logger Pro. Due to the simple and fast data acquisition process, students can gather sufficient data to plot curves of the amplitude and phase lag as a function of driving frequency.