What they didn’t tell you: (1) The whole point of Spectrasuite is to put the user in charge of the data collection. This totally open and transparent approach is in stark contrast to “user friendly” and “turn-key” instruments that dominate the lab scene. Those devices treat you like a dummy as some engineer has already made all of the critical decisions for you. In Spectrasuite you make the decisions. (2) As you make decisions, you see the effects in real time. Only when you are satisfied do you save data. (3) “Scope” mode is what you would see if you hooked up an oscilloscope to the detector on a turn-key black boxed instrument. Here we show you the actual signal, so you know whats really happening. (4) Most useful feature – and there are dozens to choose from – is the icon to capture the spectral data in the Windows clipboard. This gets wavelength vs amplitude for the active graph and any over-layed graphs. Then you can just paste them into EXCEL, if you want to process them further. (5) There are a wealth of other features and utilities. If yopu are not sure how to do something, give us a call for advice 727-230-1697.
Absorbance Measurements with Ocean Optics video Review: Good video to go over how to connect equipment and how to use the software.
What they didn't tell you: (1) They show an absorbance measurement of pure acetone in a 1 cm cuvette. This is hopelessly off scale, as the absorbance values are only quantitatively useful when they are between 0 and about 1. Above 1 the effects of stray light become increasingly large and in fact the acetone absorbance peak is simply truncated at a value of around 2. Instead, they should have used a much shorter pathlength cuvette, or they could have shown the absorbance of trace amounts of acetone in an otherwise transparent solvent such as water. (2) The used an empty cuvette as the blank, but that is quantitatively inaccurate. The "blank" or reference should be as optically as close as possible to the sample, so that absorbance is measured of just the species of interest. In the case the blank includes 4 air to quartz interfaces, while the sample had only 2 (an 2 quartz to acetone interfaces). The reflection at the interface scales to the difference in refractive index of the materials on each side, and air to quartz is much larger reflection that solvent to quartz. (3) They glossed over setting the boxcar and signal averaging values without explaining the logic. Signal to noise will increase by the square root of the number of photons sampled, and averaging across the spectra (box car) and through time (scans to average) will improve signal to noise. The drawback to signal averaging through time is waiting to get the sample. If you are patient and the sample is stable, more is better. Averaging across the spectra changes the optical resolution. Over-smoothing can lead to a blending data from adjacent absorbance peaks and systematic errors, but typically absorbance peaks in solutions are 100s of nm broad. You can increase the boxcar smoothing to match the true optical resolution (determined by the slit) without loosing information.
Color Measurement Basics with Ocean Optics video Review: Good for learning how to connect things and use the software.
What they didn't tell you: (1) The 2 degree and 10 degree observer refers to the angle illuminated by the object in a persons eye. Regular distance objects typically fill a 2 degree field of view, but objects up close can fill a 10 degree field of view. The distribution of rods and cones is not uniform, so in essence people perceive colors differently when they are close vs far. The choice in the software is used to pick from two standard CIE tables that accounts for this difference.The appropriate choice is up to you. What are they measuring and why? If you are not sure, pick 2 degrees.
LED Measurement with integrating sphere & Ocean Optics spectrometer video
Calibrating an Ocean Optics spectrometer & Integrating Sphere - Radiometry
Calibrating an Ocean Optics spectrometer and optical fiber, LS-1-CAL - Radiometry
Calibrating an Ocean Optics spectrometer and cosine corrector - Radiometery