INSTRUMENTATION

• a particle of electromagnetic radiation is known as photon
• Wavelength is inversely proportional to the frequency of

  the light wave.
• ¡ Energy is also inversely proportional to the wavelength of light
• The closer the two peaks are, the shorter the wavelength.
• The shorter the wavelength, the larger number of photons will be contained in a given distance.
• shorter wavelengths represent higher energy
• wavelength is the distance between identical points on consecutive waves
• amplitude is the distance between origin and crest or trough
• frequency is the number of waves that pass a point per unit time
• ultraviolet light is when wavelength falls below the visible region of 190-340 nm
• visible light is when wavelength falls within 340-700 nm
• beer-lambert's law states that the concentration of a substance is directly proportional to the amount of light absorbed
• beer-ambert's law also states that the concentration of a susbstance is inversely proportional to the logarithm of the light transmitted
• the relative amount of light passing through the sample is known as transmittance
• Absorbance is the relative amount of light absorbed by the sample and is related to transmittance
• spectrophotometry is the measurement of the light transmitted by a solution to determine the concentration of the light-absorbing substance in the solution
• entrance slit prevents scattered light from entering the monochromator
• monochromator is a device that produces light of specific wavelengths from a light source
• bandpass determines the efficiency of monochromator
• interference filter is used when only light with desired wavelength which is reflected twice will be in phase and come out of the filter
• photodetectors converts transmitted light energy into an equivalent amount of electrical energy
• atomizer breaks up the solution into finer droplets so that the atom will absorb heat energy from the flame and get excited
• Na filter transmits only yellow light (589 nm)
• K filter transmits only violet light (367 nm)
• Lithium transmits only red light (767nm)
• flame emission measures the radiation emitted by the excited atoms that is related to concentration
• atomic absorption measured the radiation absorbed by the unexcited atoms determined
• luminescence is the emission of light by a substance. It occurs when an electron returns to the electronic ground state from an excited state and loses its excess energy as a photon.
• a beam of light is incident on certain substances they emit visible light or radiations is known as fluorescence.
• phosphorescence is when light radiation is incident on certain substances they emit light continuously even after the incident light is cut off.
• TURBIDIMETRY - measures the amount of light blocked in a particulate suspension
• NEPHELOMETRY - measures the amount of light scattered
• Light symmetrically scattered around the particle - RAYLEIGH
• Light scatters backward but appears forward due to destruction out of phase background scatter - MIE
• More forward light scatter, Antigen-antibody reactions - RAYLEIGH DEBYE