Smoke detection in air: Difference between revisions
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== Lock-In Amplifier == | == Lock-In Amplifier == | ||
Measure small signals in a large background (huge noise). | Measure small signals in a large background (huge noise). | ||
[[File:SMOKE1.png|400px|center]] | [[File:SMOKE1.png|400px|center]] | ||
=== Mathematical Description === | === Mathematical Description === | ||
[[File:SMOKE2.png|500px]][[File:SMOKE3.png|500px]] | [[File:SMOKE2.png|500px]][[File:SMOKE3.png|500px]] | ||
=== Signal Process === | === Signal Process === | ||
[[File:SMOKE4.png|500px|center]] | [[File:SMOKE4.png|500px|center]] | ||
=== Logic Flow === | === Logic Flow === | ||
| Line 22: | Line 26: | ||
== Experiment == | == 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. | 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 === | === Component List === | ||
| Line 31: | Line 36: | ||
: 6) Resistor (1.2K) | : 6) Resistor (1.2K) | ||
: 7) LED (Green) | : 7) LED (Green) | ||
=== Schematics === | === Schematics === | ||
[[File:SMOKE10.png|1200px|center]] | [[File:SMOKE10.png|1200px|center]] | ||
=== Detection Setup === | === Detection Setup === | ||
[[File:SMOKE_SETUP.jpg|800px|center]] | [[File:SMOKE_SETUP.jpg|800px|center]] | ||
In this part, we use BWP34 Silicon PIN Photodiode as the detector. Here the capacitor and resistor are used to protect the photodiode. | 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 === | === Lock-In Amplifier Setup === | ||
[[File:LOCKIN1.jpg|600px]] [[File:LOCKIN2.jpg|600px]] | [[File:LOCKIN1.jpg|600px]] [[File:LOCKIN2.jpg|600px]] | ||
[[File:LOCKIN3.jpg|600px]] [[File:LOCKIN4.jpg|600px]] | [[File:LOCKIN3.jpg|600px]] [[File:LOCKIN4.jpg|600px]] | ||
=== Video === | === 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. | 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. | ||
<p>[[Media:SMOKE_VIDEO.mp4]]<p/> | <p>[[Media:SMOKE_VIDEO.mp4]]<p/> | ||
=== Data Plot === | === Data Plot === | ||
[[File:SMOKE11.png|1200px|center]] | [[File:SMOKE11.png|1200px|center]] | ||
=== Error Analysis === | === Error Analysis === | ||
== Further Discussion == | == Further Discussion == | ||
== Reference == | == Reference == | ||
Error Analysis in Experimental Physical Science: https://faraday.physics.utoronto.ca/PVB/Harrison/ErrorAnalysis/ErrorInMean.html | Error Analysis in Experimental Physical Science: https://faraday.physics.utoronto.ca/PVB/Harrison/ErrorAnalysis/ErrorInMean.html | ||
Revision as of 15:00, 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.
Data Plot
Error Analysis
Further Discussion
Reference
Error Analysis in Experimental Physical Science: https://faraday.physics.utoronto.ca/PVB/Harrison/ErrorAnalysis/ErrorInMean.html