Pressure Indicator

Introduction

Keeping auto tires properly inflated optimizes tire performance and fuel economy. An underinflated tire cannot maintain its shape and builds up excessive heat potentially leading to tread separation. Underinflation increases rolling resistance, and reduces steering precision and cornering ability. An overinflated tire is stiff and unyielding, resulting in a harsher ride. It is much more susceptible to damage when running over a pothole or debris in the road. In 2000, all new cars in the US were required to have a built-in tire pressure monitoring system to warn drivers when underinflation reached 25%. The minimum requirement was that all cars have a warning light on the dash, however more elaborate systems also indicate wheel position. As a STEM extension to the “Gas Pressure and Volume” experiment, you will use a Vernier Gas Pressure Sensor and Digital Control Unit (DCU) to simulate an auto tire pressure monitoring system.

Objectives

• Turn on an LED when the reading from a Gas Pressure Sensor drops below 10 psi.
• Control a sensor-based system with the DCU.

Reference Experiment

• “Gas Pressure and Volume” – Experiment 30 from Physical Science with Vernier
• “Fun with Pressure” – Experiment 19 from Middle School Science with Vernier
• “Boyle’s Law” – Experiment 6 from Chemistry with Vernier