In: Physics
Spectrometer Lab
Summarize this experiment from purpose to procedure to analysis.
Include all important theoretical equations.
{¶ ≤ 100 words}
Spectrophotometer calibration is a process in which a scientific
instrument known as a spectrophotometer is calibrated to confirm
that it is working properly. This is important, as it ensures that
the measurements obtained with the instrument are precise and
accurate. The procedure varies slightly for different instruments,
with most manufacturers providing a detailed calibration guide in
the owner's manual so that people know how to calibrate the
equipment properly. When this process is performed, the person
doing it must make a note in the log attached to the equipment and
in their experimental notes, so that people know when the device
was last calibrated and handled, and by whom.
A spectrophotometer is capable of both transmitting and receiving
light. The device is used to analyze samples of test material by
passing light through the sample and reading the intensity of the
wavelengths. Different samples impact the light in different ways,
allowing a researcher or technician to learn more about the
materials in the test sample by seeing how the light behaves as it
passes through the sample. Spectrophotometer calibration is
necessary to confirm that the results are accurate.
In spectrophotometer calibration, a reference solution is used to
zero out the equipment. This solution provides a base or zero
reading. The device is calibrated by placing the reference solution
inside the spectrophotometer, zeroing out the settings, and running
the instrument. Then, samples of an actual test material can be
subjected to spectrophotometry in confidence that the machine has
been calibrated and is working properly.
In a single beam spectrophotometer, a single beam of light is
generated, and the device must be recalibrated for each use. In a
double beam spectrophotometer, beams can be sent through a test
sample and a reference sample at the same time to generate two sets
of results which can be used for reference and calibration. In
either case, spectrophotometer calibration can be done in the lab
by someone working with the machine. If the machine develops
serious problems, it may be sent to the manufacturer for
maintenance, repair, and potential replacement.
In order for a spectrophotometer to work properly, it must be
allowed to warm up before use. Many devices take around 10 minutes
to warm up. It is important to avoid performing spectrophotometer
calibration during the warmup phase as this will throw the settings
off. It is also important to be aware that for certain types of
wavelengths, special filters and attachments may be needed for the
device to function.