![]() ![]() Display a condensed summary of the spectra in the view. View and modify the information stored with the spectrum. Choose between overlay or individual normalize when viewing multiple spectra. Following are the functions of the other buttons: Select the active data file from those in the view. Toggle between zoom and trace functions of the mousecontrolled cursor. In trace mode the cursor displays the wavelength position and CD value. Alternatively, the cursor zoom mode may be selected the normal mouse operations of left-click-hold-and-drag can then be used to resize the display as required. Ordinate and abscissa may be scaled by selecting X or Y and the actions of the various buttons. 9ġ0 The display may be manipulated using the various elements shown in the ribbon bar. Spectra Analysis views of memory 1 and memory 2, background and camphor. The most recently acquired spectrum automatically opens in Spectra Analysis at the top of the stack. Analyzing Data Each spectrum acquired may be stored in memory and viewed (i.e memory#1, memory#2 et cetera), or automatically saved on disk, depending upon the options selected on the spectrum measurement -> parameter -> data file tab. When the measurement is completed, the software will automatically open and transfer the results to the Spectra Analysis program. 4ĩ The data acquisition is displayed in real time in the Spectrum Measurement view. Normal instrument start-up after selecting Spectrum Measurement After completing the diagnostics, the software presents the Spectrum Measurement" view. WARNING: If the HT check fails, don t worry about it, but If any of the other diagnostic tests fail, do NOT attempt to fix the problem! Immediately cease operation of the instrument, return it to a safe mode by following the normal shutdown steps discussed later in this document, and notify Dan or Tibi. After it finishes, it will turn the lamp on. The Spectrometer will display a five min countdown for N2 purge. The diagnostic tests will not be discussed in this document. This causes the software to perform a number of automatic diagnostic tests, and to download default measurement parameters to the spectrometer. ![]() Preparing for Data Acquisition From the list of measurement programs presented in the Spectra Manager menu, double-click Spectrum Measurement. Replace the black sample holder cap close the sample compartment lid. Lift the sample compartment lid remove cap from sample holder place cuvette in holder. Each of these will be discussed in later sections. ![]() Start the Jasco program A suite of programs will be displayed, including five analysis programs, and eight measurement programs. Double-click the Jasco Spectra Manager icon to start the program. This will usually be your boss s last name. Computer access Log in to the computer with your assigned username. You should turn on the Peltier controller and water Bath. N2 flowrate depending on the wavelength range: Spectral Flow Rate Limit 175 nm 30 l/m 180 nm 15 l/m 200 nm 7 l/m Spectrometer power After the ten minutes N2 gas purge, the instrument may be turned on (green switch). Open N2 shut-off valve check flow (> 6 l/min) Regardless of the spectral region being investigated, the instrument must be purged for al least fifteen minutes before the instrument is turned on. At least 15 minutes prior to use, the nitrogen gas valve must be turned on. Nitrogen gas is used to purge air from the instrument optics. These effects increase as the wavelength is decreased. 1Ģ Startup Nitrogen gas - Strong UV radiation produced by the source can create levels of ozone damaging to the optical elements unless steps are taken to remove oxygen from the instrument. Although the PC is normally on at all times, the J-810 is normally OFF except when in use. A linear crystal oscillating at 50 khz creates circularly polarized light which is directed through the sample compartment, and detected by a photomultiplier tube. Mirrors, prisms, and slits are used to select frequency elements. The instrument uses a high intensity UV lamp to provide energy in the wavelength region from below 180 nm to above 700 nm. Jasco J-810 CD Spectrometer Overview The J-810 is controlled by a Windows 7 PC communicating via two serial ports, one to the instrument and one to the Peltier temperature control accessory. The use of long path length liquid or gas cells requires removing the Peltier device and should only be done by Dan or Tibi. Spacers are included to accommodate smaller cuvettes. The system will accept a number of sample devices, but the default is a Peltier controlled thermostated cell holder designed for standard 1cm x 1cm quartz cuvettes. 1 Introduction The Jasco J-810 CD is a research grade instrument used for measuring the circular dichroism of compounds in solution, including small molecules, peptides and proteins. ![]()
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