Smoke detection in air: Difference between revisions

From PC5214 wiki
Jump to navigation Jump to search
No edit summary
No edit summary
Line 49: Line 49:
=== Data Plot ===
=== Data Plot ===
[[File:SMOKE11.png|1200px|center]]
[[File:SMOKE11.png|1200px|center]]
=== Error Analysis ===


== Further Discussion ==
== Further Discussion ==

Revision as of 14:59, 28 April 2022

Introduction

Smoke detector is a device that senses smoke, typically as an indicator of fire. Commercial smoke detectors issue a signal to a fire alarm control panel as part of a fire alarm system. Household smoke detectors, also known as smoke alarms, generally issue an audible or visual alarm from the detector itself or several detectors if there are multiple devices interlinked [1].


Lock-In Amplifier

Measure small signals in a large background (huge noise).

Mathematical Description

Signal Process

Logic Flow


Experiment

We can divide this experimental setup into two parts: the first part will detect the scattering light in the air, and the second part will amplify such signal.

Component List

1) DC Voltage source (MATRIX MODEL: MPS-3005L-3)
2) MODEL SR830 DSP Lock-In Amplifier
3) BWP34 Silicon PIN Photodiode
4) WAVESURFER 104MXS Oscillator
5) Capacitor (50V 22uF)
6) Resistor (1.2K)
7) LED (Green)

Schematics

Detection Setup

In this part, we use BWP34 Silicon PIN Photodiode as the detector. Here the capacitor and resistor are used to protect the photodiode.

Lock-In Amplifier Setup

Video

In this video, we have recorded the voltage change in the lock-in amplifier under the situation when the smoke (vaporised tin) gradually drifts in, maintains and finally disappears.

Media:SMOKE_VIDEO.mp4

Data Plot

Error Analysis

Further Discussion

Reference

Error Analysis in Experimental Physical Science: https://faraday.physics.utoronto.ca/PVB/Harrison/ErrorAnalysis/ErrorInMean.html