![]() How do I get an A260/A280 value with your UV-VIS spectrometers in Logger Pro? Why can't my device find Go Direct Spectrometer when I try to connect via Bluetooth?ĭo you have labs written for your spectrophotometers?Ĭan I do blackbody experiments with the Vernier or Ocean Optics Spectrometers?ĭo you have a spectrometer that can measure DNA concentration and purity?Ĭan I use my spectrometer to collect data at one wavelength (kinetics or Beer's law)? The power LED indicator light on my UV-VIS or Fluorescence/UV-VIS Spectrometer is red. Spectral Analysis Troubleshooting and FAQs It won't calibrate or is giving very noisy data. Is there a way to toggle on/off the colored background behind the absorbance spectrum graph? My spectrometer is connected to a device and I get the error message, "Could not collect values from device," or "calibration failed" during calibration. ![]() Why are there blank data table cells in my spectrometer absorbance data? Why is the maximum sample time for a spectrometer set at 1000 milliseconds? How do I check the lamp output of my spectrometer?Ĭan my Vernier-branded spectrometer be reconditioned? Can the lamp in my spectrometer be replaced? What is the difference between the types of cuvettes you sell for Spectrometers and the Colorimeter? What cuvettes can I use in my UV-Vis or Fluorescence/UV-VIS Spectrophotometer?Ĭan I order a custom LED for the Fluorescence/UV-VIS Spectrometer? What are some tips for improving my Fluorescence/UV-VIS Spectrophotometer data? ![]() To avoid this, it is best to perform fluorescence measurements on samples that have an absorbance below 0.1. The inner filter effect results in an apparent decrease in emission quantum yield and/or distortion of bandshape as a result of reabsorption of emitted radiation. In fluorescence measurements, the inner-filter effect is always a consideration.This will help save your deuterium lamp for absorbance measurements. If you plan on only taking fluorescence data, the power cable does not need to be attached, nor does the power switch need to be on.Review What are some tips for improving my Fluorescence/UV-VIS Spectrophotometer data? Collect a spectrum with a known sample where the absorbance falls between 0.1 and 1.0 absorbance units. Calibrate the spectrometer with the appropriate solvent.Ħ. Set the spectrometer to collect data in absorbance vs wavelength mode, if not already done.ĥ. The latest version of software is available as a free download here: Ĥ. Options include: Logger Pro 3, LabQuest App, and Spectral Analysis. Start the appropriate data-collection software. Note: Do NOT plug the USB into a computer USB port to run with Bluetooth.ģ. If connecting via bluetooth (Go Direct version only): Connect the spectrometer to the USB power adapter or to a powered USB hub. If connecting via USB: Connect the spectrophotometer directly to the USB port. Wait for the lamp indicator LED to remain green.Ģ. Turn the power switch to the ON position. Connect the AC power supply to the spectrophotometer. For general instructions, see Specifications and User GuideĪre you using LabQuest App v2.8.8 or v3.0.5, or Spectral Analysis v4.11, Logger Pro 3.16.1 or newer?ġ. It was sold between January 2017 and January 2022. ![]() The Vernier Fluorescence/UV-VIS Spectrophotometer is no longer available for purchase. There are two types of reasons for nonlinearity, chemical and instrumental.Go Direct Fluorescence/UV-VIS Spectrophotometerįor general instructions, see Specifications and User Guide The rule of thumb that we will use in this lab applies only to the spectrometers we use, and that is that we can only trust values between A= 0.05 and A=1.0. The extinction coefficient is often a very large number which allows one to measure very small concentrations of solute, and it is a property of the molecule, but is influenced by the solvent.īeer's Law is linear over a small range of absorbances and you can not believe all readings a spectrometer gives you. Where A is the unitless absorbance, I o is the intensity of light entering the sample, I t is the intensity of light transmitted out of the sample, b is the path length, c is the concentration of the molecule absorbing the light and \(\epsilon\) is the extinction coefficient and has the units of concentration -1 length -1. So after converting to log base 10 (which is done for historical reasons) we get
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