# Shared Flashcard Set

## Details

Lab Instrumentation
Basic Laboratory Equipment
27
Health Care
06/05/2010

Term
 MicroPipette
Definition
 -May or may not have bulb or taper -Calibrated to contain a set volume -total holding volume of less than 1 ml
Term
 Factors determining the type of pipette..
Definition
 -Viscosity -accuraccy desired -volume to be used -What solution/fluid being pipetted
Term
 What is visible light?
Definition
 The portion of the electromagnetic spectrum that eyes can see.
Term
 Nature of light
Definition
 Wavelengths of radiant energy visible or invisible to the human eye.   A wavelength of light is defined as the distance between two peaks, measured in nanometers(nm), as it travels in wavelike patterns.
Term
 Visible Spectrum
Definition
 Color of light depends on the wavelength that is NOT ABSORBED   What is not absorbed is transmitted.
Term
 Wavelength of <380 (Ultraviolet)
Definition
 Not Visible
Term
 380-440 440-500 500-580 580-600 600-620 620-750
Definition
 Violet Blue Green Yellow Orange
Term
 >750
Definition
 Not Visible (Infared)
Term
 Sources Of Light
Definition
 Most Common Sunlight, incandescent tungsten or tungsten iodide lamp.
Term
 Lamps most commonly used for Ultraviolet work
Definition
 Deuterium- discharge lamp or the Mercury-Arc Lamp
Term
 BEERS LAW
Definition
 Concentration of a substance is directly proportional to the amount of light absorbed or inversly proportional to the logarithm of light transmitted.
Term
 Cu= (Au)(Cs)         As
Definition
 Concentration of the unknown equals Absorbance of the Unknown(Au) Times the Concentration of Standard(Cs) Divided By The Absorbance of Standard.
Term
 Percent Transmittance(%T)
Definition
 The Ratio of the radiant energy transmitted(T), divided by the radiant energy incidental(I) on the sample, Expressed as %.
Term
Definition
 Light initially directed  toward a sample
Term
 Transmittance
Definition
 A measure of the Fraction of initial Radiant Power P0 the passes through a sample, Emerges (p)and reaches a detector.
Term
 Absorbance(A)
Definition
 The amount of light ABSORBED   Cannot Be  Measured Directly, But is Mathmatically Derived From %T as it is directly proportional to concentration.
Term
 Absorbance
Definition
 A Measure of the amount of Radiant Power absorbed by the sample   -Indirectly Proportional t Transmittance -Directly Proportional to Concentration
Term
 Colorimety
Definition
 Methods of measuring concentration by reference to the absorption or transmission of light. Visual-Interperated by the human eye Photoelectrical- Interperated by machine
Term
 Spectrophotometer
Definition
 Instrument used to measure the light transmitted by a solution in order to determine the concentration of the light absorbing substance in the solution.
Term
 Light source of Spectrophotometer
Definition
 A device which provides EMR in a broad spectrum. (Source of Light) Visible and IR- Incandescent Tungsten or Tungsten Iodide Lamp UV- Deuterium Discharge Lamp or Mercury Arc Lamp
Term
 Maintenence of light source for Spectrophotometer
Definition
 Recalibrate when lamp is changed -Changes the angle of the light striking the monochromator -Angle change causes the color of the light striking the cuvet to be changed.
Term
 Monochromators
Definition
 Device for selecting a range of wavelengths, surrounding the specified wavelength.   Isolation of individual wavelength is important and necessary for function.
Term
 Types of Monochromators
Definition
 -Colored Glass Filters -Interference Filters -Prism -Diffraction Gratinng (Most commonly used)
Term
 Colored Glass Filters
Definition
 Least Expensive Usually pass a relatively wide band of radiant energy and have a low transmittance of the selected wavelength. Not precise. Simple and useful.
Term
 Cuvette
Definition
 Sample cell-a place to hold the sample being analyzed.
Term
 Tor F: Quartz Cuvettes must be ised for requiring ultraviolet radiation.
Definition
 True
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