Spectrometers, Sensors & Accessories
spectroscopy for a changing planet
Applications & Spectra
This applications journal is provided to give you some ideas on how to make optical sensing experiments. This is a somewhat random selection gathered from helping our clients deploy more than 100,000 spectrometers, phase fluorometers and other fiber optic sensing systems world wide. Please feel free to copy any of the spectra you see. Credit to Spectrecology would be appreciated, a link to our website would be even better! If you need the actual data or help with the application please feel free to contact us.
In no apparent order....
Fluorescence with 365nm Excitation
In no apparent order....
Fluorescence with 365nm Excitation
Reflection Probe Fluorescence using 365nm Excitation
Fluorescence from solids or liquids is easy to measure with a fiber optic reflection probe. This versatile device has a bundle of fibers in a close packed 6 around 1 arrangement. The fibers are fixtured into a 1/4" diameter steel ferrule. The fibers are routed into 2 legs: the six outside fibers are the illumination leg and the inner fiber is the detection leg. In air the filed of view is ~25 degrees, in water its ~12 degrees. The sampled area of solids can be controlled by adjusting the distance from the probe to the surface. In liquids there is a sampled volume with the signal being the strongest from the nearest overlap region and diminishing as you move further way. In clear fluids the sampled volume may extend a few cm. In turbid fluids it will be much less. The best probe to use is one made from 600 um fibers, although 400 micron fibers will work as well.
The reflection probe is connected to our LLS-365 source for excitation. This is a powerful UV LED that can be used for a wide variety of fluorophores. The detection leg is connected to a USB4000-FL spectrometer. The spectrometer measures from ~350 - 1000nm with about a 5nm bandpass. It is set up for maximum sensitivity by using a 200 um slit and a collection lens on the detector. Here is a picture that shows the essentials. The reflection probe is in a holder to orient it at 45 degrees to the surface of a solid. This also keeps out room light.
Fluorescence from solids or liquids is easy to measure with a fiber optic reflection probe. This versatile device has a bundle of fibers in a close packed 6 around 1 arrangement. The fibers are fixtured into a 1/4" diameter steel ferrule. The fibers are routed into 2 legs: the six outside fibers are the illumination leg and the inner fiber is the detection leg. In air the filed of view is ~25 degrees, in water its ~12 degrees. The sampled area of solids can be controlled by adjusting the distance from the probe to the surface. In liquids there is a sampled volume with the signal being the strongest from the nearest overlap region and diminishing as you move further way. In clear fluids the sampled volume may extend a few cm. In turbid fluids it will be much less. The best probe to use is one made from 600 um fibers, although 400 micron fibers will work as well.
The reflection probe is connected to our LLS-365 source for excitation. This is a powerful UV LED that can be used for a wide variety of fluorophores. The detection leg is connected to a USB4000-FL spectrometer. The spectrometer measures from ~350 - 1000nm with about a 5nm bandpass. It is set up for maximum sensitivity by using a 200 um slit and a collection lens on the detector. Here is a picture that shows the essentials. The reflection probe is in a holder to orient it at 45 degrees to the surface of a solid. This also keeps out room light.
Here are some sample spectra. The photopigments in plants are always quite interesting. The main pigment is chlorophyll, but accessory pigments help harvest light and also give various colorations to the leaves. These are spectra taken in the green and yellow areas of the front surface, and the back surface. The green area has equal peaks at 690nm and 750nm, yellow has a strong peak at 690 and the back somewhat higher at 690nm.
