Spectrophotometer Flashcards
These are instruments that measure light energy. Examples are spectrophotometers, FEP, AAS
Optical Instruments
Kind of light at 400-700nm
Visible spectrum
Less than 400nm
UV
Greater than 700nm
IR
This energy transmitted via electromagnetic waves characterized by frequency and wavelength
Ligh Energy
Wavelength is ________ proportional to energy
Inversely Proportional
What do you use to check wavelength accuracy?
Didymium / Holmium Oxide Filter
Order of wavelength in Visible Light
“VIBGYOR” 400 to 700 nm
Red = High WL, Low Energy
Violet = Low WL, High Energy
Spectrophotometer: Concentration of substance is _____ to the amount of light absorbed and _____ to the log of transmitted light.
Spectrophotometer: Concentration of substance is DIRECTLY PROP to the amount of light absorbed and INDIRECTLY PROP to the log of transmitted light.
This prevents stray light
Entrance Slit
Type of light source that emits radiation that changes in intensity
Continuum Source
Type of light source that has limited radiation and wavelength
Line Source
Indicate IR light sources
Merst-Glower
Globar
Indicate VIS/IR light source
Tungsten-Halogen Lamp
Indicate UV light sources
Mercury Arc Lamp
Deuterium Discharge
Xenon Arc Lamp
Hydrogen Lamp
This is the most common cause of loss of linearity, dispersion of second-order spectra
Stray Light
This controls the width of light beam /bandpass
Exit Slit
This part of the spectrophotometer isolates the wavelength
Monochromator
Type of monochromator with purest UV
Prisms
Most sensitive and most common monochromator
Fraction Gratings
Least expensive mmonochromator
Colored glass filters
Indicate all examples of monochromators
Prisms
Fraction Gratings
Interference filters
Colored Glass Filters
This part of the spectrophotometer converts transmitted light to electrical energy for easier measure than light
Photodetectors
This is an internal current photodetector
Barrier-Layer Cell / Photocell / Photovoltage
Most Sensitive and most common photodetector; DYNODES
Photomultiplier
External and multichannel photodetector
PhotodiodeCa
Cathode Anode Photodetector
Phototube
Factors for choosing a light source:
Range, Spectral, Source, Stability, Temp
Most common type of sample holder/cuvette used and why
Square-end. Path length needs to be the same, easier to do for square
Most common example of cuvette
Alumina SIlica Glass
Enumerate all examples of cuvettes
Alumina-Silica Glass
Quartz-Plastic (for UV)
Borosilicate Glass
Soft Glass
