The current model LS 6500 (and LS6000 for that matter) Scintillation Counter offers unparalleled flexibility in a single high performance system, without the need of a dedicated external computer. Advanced electronic components, such as a Motorola 68000 Series microprocessor supported by a digital signal processor, maximize technological lifetime and make the LS 6500 fast and efficient.
(NOTE: The specifications, functionality, and styling for the LS 6000 is essentially the same as the LS 6500 at lower cost!)
A 32,768 channel multichannel analyzer gives you an eight-fold improvement in effective resolution (0.06 keV per channel) over that of conventional liquid scintillation counters (0.5 keV per channel). This provides the basis for:
Functionally very similar to the LS5801 / LS3801 with additional sophistication. Selection of programs is also accomplished through the use of command cards, but the process of editing user programs is somewhat different.
Additional functionality for the 6500 include improved counting efficiency of dry scintillant (eg ReadyCaps); a reversible belt carrier system that allows for more convenient recounting of samples; counting single racks without command card (under interrupt in the Multi Task menu), single photon counting, and dual label studies. Entering user programs involves selection of isotopes to set spectrometer windows rather that actual window energies. Thus, if you wish to count tritium in channel 1 you would select 3H for isotope one (actually this is the default). If you wish to manually set the window you may do so by entering Manual in this field. Please refer the the manual for detailed instructions.
It is important to note that if are doing a dual labeling study you should choose Isotope 1 as the lower energy isotope and Isotope 2 as the higher energy isotope. The lower limit for Isotope 2 is set the same as the upper limit for Isotope 1. Don't define multiple isotopes in singlely labeled studies as it will result in lowered counts.
The LS 6500 guides you with ease-to-follow menus and context-sensitive help screens. Operate the system without an external computer.
User Interface and Output
LSC (liquid scintillation counting) is dependent on the interaction of an energetic particle with an organic compound, the scintillant. This interaction results in a photon(s) which are detected up by a photomultiplier(s) and usually displayed as counts per minute (CPM). Both the LS3801 and LS6500 / LS6000 instruments count samples in a liquid format, either in the standard 20 ml glass or plastic vial or in a 6 ml miniature vial. Only the Model 6500 can be programmed to accurately count dry samples, such as the Beckman ReadyCap. If you are using these insure that you have programmed the instrument properly.
Parameters that you should be prepared to enter include the count time, sample repeat and count channel as well as the radioisotope you are observing. Programs are selected by the use of command cards which are inserted in the first rack. Racks may also be numbered, but this is optional, by the use of special rack number cards. It is possible that a suitable program exists for your application, but confirm that you understand what the program is counting and any calculations it may be performing on your data.