CHEM 3530U Lecture 1: CHEM3530- INST ANALYTICAL CHEMISTRY- entire course notes
How do we get signal and read things: and LED display
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Magnifying crtain wave length
Electron multipliers
Familiar with how info gets encoded, data
domains is how it can be coded
Lecture 2- sept 16
Wednesday, September 16, 2015
11:12 AM
analytical Page 1
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Non electrical domains: ex mass, things with a ruler
Electrical domains: ex voltage
Measurement begins and ends in the non-electrical domains
Valuable to be able to keep track of switching different
domains and converting
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Transducing information from one domain to the other
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Any measurement process can be represented as a series
of inter domain conversions
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Input and output transducer
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Input takes non-electric and outs it to electric
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Output takes electric and makes it non-electric domain
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General set up
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Particular intensity, some response by chemical or physical
properties (non-electric domain)
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Fluorescence is non-electric, hits the transducer and
converts
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Converts to something praportional in intensity to electric,
does voltage with is electric and then spits out a # which is
non electric something we can read
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Start in physical and chemical domain
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Converted to current by input transducer
1.
Current, intensity of florescence is proportional to current
2.
Makes voltage proportional to current
3.
Gives the reading
4.
Start end non-electric domain
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Critical are transducers which switch between the 2
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analytical Page 2
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Theres a lazer pointer when you open it, it
interupts the signal and the chime goes off
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Ex when you go into a store and it dings
1.
Photo electric detector, if smoke appears, it
goes infront of LED and disrupt the signal
and it sets alarm off. Wouls take a lot of
smoke to set this off
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Or is you put smoke in front of light it
scatters the light, so they have the detector
on the ground so a little smoke will scatter
the light and it will set off the alarm
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In presence of lots of smoke, photocurrent
decreases
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In presence of smoke, light is deflected and hits
sensor, more sensitive
The dectror (photo diod) is the ouput
transducer
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What is the output transducer in some case?
battery powered
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2 metal plates, has a tiny radioactive source
ionizes the air in-between the 2 metal plates that
creates a current
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Smoke gets in it deionizes some and disrupts and
then it beeps
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Ionizes Oxygen between plates to produce
current
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Smoke neutralizes ions
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Detector senses a drop in that current
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Alarm sounds
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Whats transducer? Say detector but combination
of the 2 plates and Oxygen between it because it is
what interprets
Different stuff in smoke or air will react that’s
how it neutral the ions
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analytical Page 3
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
How do we get signal and read things: and led display. Familiar with how info gets encoded, data domains is how it can be coded analytical page 1. Non electrical domains: ex mass, things with a ruler. Measurement begins and ends in the non-electrical domains. Valuable to be able to keep track of switching different domains and converting. Transducing information from one domain to the other. Any measurement process can be represented as a series of inter domain conversions. Input takes non-electric and outs it to electric. Output takes electric and makes it non-electric domain. Particular intensity, some response by chemical or physical properties (non-electric domain) Fluorescence is non-electric, hits the transducer and converts. Converts to something praportional in intensity to electric, does voltage with is electric and then spits out a # which is non electric something we can read. Current, intensity of florescence is proportional to current. Critical are transducers which switch between the 2 analytical page 2.
