C-7100 Series User Manual PEAK INSTRUMENTS INC.
-
2 -
depends on the two monochromatic molar absorptivity difference
△
ε, |
△
ε | is very small, can be approximated that
monochromatic, at low concentrations, curve remains linear, but larger concentrations, with concentration increases, AC
curve bend more serious, there is Beer's law applies only to dilute solutions
F.
Stray light, stray light entering the detector means is unnecessary components to be tested at other wavelengths
outside the range of the wavelength spectral bandwidth. The main dispersive element from a prism or grating
spectrometer, a mirror, a lens surface scattering, dust and other inner walls of monochromator components and
diffuse reflection and other scars, the stray light can cause serious measurement error. The instrument is the
smallest wavelength of energy, usually at a maximum stray light (such as deuterium lamp 220nm, tungsten lamp
340nm)
G.
Slit width, the slit width of the spectrum affects not only the purity, but also affect the absorbance. When
quantitative analysis in order to obtain sufficient measuring signal, the slit should be larger, in the qualitative
analysis of the use of a smaller slit when the entrance slit and the exit slit width equal to the width of the slit caused
minimum error
H.
Wavelength scale ruler of error, the wavelength of the gauge that wavelength accuracy of the instrument, such
as a large error or correction, the spectral measurements produce errors that affect the accuracy of absorbance
measurements (in the absorption spectrum of the peak of the more significant )
I.
Impact of non-parallel incident, one of the prerequisites ear than the law is the use of a parallel incident beam to
ensure that all beams through the same thickness of the absorbing medium, when a large deviation from
parallelism when the incident beam, obviously lead to deviations from Beer's law. If the instrument is in moderate-
intensity beam deviation from parallelism, absorbance measurement error is generally caused by less than 0.5%
J.
Photometric scale error, photometric accuracy of the scale that is transmittance, which directly affects the
accuracy of the magnitude of the error photometric measurements.
