Colorimeter Circuit

A colorimeter comprising a light source, an operational amplifier, a reference photoconductive cell connected between the input and output of the amplifier and a sample photoconductive cell connected to the input of the amplifier. The amplifier provides an output signal which is a function of the ratio of the amount of light falling on the reference photoconductive cell to the amount of light falling on the sample photoconductive cell. The output of the amplifier is connected to a suitable measuring device such as a meter or recorder which provides a measurement of the output signal.

Link to Journal:

Image Colorimeter

A colorimeter includes an objective for focusing an object image on a first half of a viewing screen. A standard light reference beam is projected onto the second half of the screen. A moving shutter alternately blocks the first half then the second half of the screen. A light detector is responsive to the alternating images on the screen as they pass through color filters. The detector output may provide

Specific wavelengh colorimeter

A self contained, specific wavelength, single beam colorimeter for direct spectrophotometric measurement of the concentration of a given solute in a test sample. An electrical circuit employing a photoconductive cell converts the optical output into a linear, directly readable meter output. The colorimeter is simple to operate and is adapted for use in zero gravity conditions. In a specific application, the colorimeter is designed to analyze the concentration of iodine (I.sub.2) in potable water carried aboard a space vehicle such as the IVB stage of Skylab.


http://search.proquest.com/ante/docview/35170404/1414B053D333660CFC/10?accountid=10594#

Spectrophotometric Analysis of a Two-Component System with Overlapping Spectra by Walter Rohr

A number of methods have been developed to determine the composition of a binary
mixture spectrophotometrically. Most of these are directed at mixtures where one
component can be isolated from the other or they require a Beer’s law experiment to
measure the molar absorptivity of each of the substances in the mixture. However,
Blanco 1, et. al. described a method of resolving mixtures with overlapping spectra, called
Multi-Wavelength Linear Regression Analysis or MLRA, without determining molar
absorptivities or complicated mathematics. Using Blanco’s method, the composition of a
binary mixture with overlapping spectra can be resolved with only three measurements,
the absorbance of a standard solution for each component, and the unknown mixture
itself. Vernier’s Logger Pro software is ideally suited for this experiment with the ease at
which one can manipulate data and its ability to prepare a graph even when the data are
out of order


http://www.vernier.com/files/innovate/spectralanalysis3.pdf

Table of Characteristic IR Absorptions

frequency, cm–1	bond	functional group
3640–3610 (s, sh)	O–H stretch, free hydroxyl	alcohols, phenols
3500–3200 (s,b)	O–H stretch, H–bonded	alcohols, phenols
3400–3250 (m)	N–H stretch	primary, secondary amines, amides
3300–2500 (m)	O–H stretch	carboxylic acids
3330–3270 (n, s)	–C(triple bond)C–H: C–H stretch	alkynes (terminal)
3100–3000 (s)	C–H stretch	aromatics
3100–3000 (m)	=C–H stretch	alkenes

Nanometer-Scale Sizing Accuracy of Particle Suspensions on an Unmodified Cell Phone Using Elastic Light Scattering

Mobile technologies have been advancing at a rapid pace, with current mobile platforms' computing power approaching that of desktop machines. These advances in device computing have come alongside progress in mobile imaging technology, with current cell phone cameras using sophisticated back-thinned CMOS sensors coupled to high quality optics with relatively high numerical apertures. This progress has led several groups to explore the possibility of performing medical diagnostics, such as microscopic imaging [1]–[3], cell counting [4], and spectroscopy [2], using mobile devices. We present in this paper an attachment to a cellular phone that allows for accurate sizing of particles using elastic light scattering.

Link to Journal:

Spectrophotometric Analysis of a Two-component System with Overlapping Spectra

http://www.vernier.com/files/innovate/spectralanalysis3.pdf

code working in protoype v1

// Spectrometer_led10
// clear the LCD
void clearLCD() {
Serial.print("");
delay(1);

Colorimeter design arduino

Colorimeter Article

Specific Wavelengh Colorimeter
http://search.proquest.com/ante/docview/35170404/1414B053D333660CFC/10?accountid=10594#

Image Colorimeter
http://search.proquest.com/ante/docview/31788233/1414B053D333660CFC/23?accountid=10594

Colorimeter Circuit
http://search.proquest.com/ante/docview/35663530/1414B053D333660CFC/36?accountid=10594