Friday, January 04, 2008

Whether one is using a spectrophotometer for sample analysis in the visible range or in the ultraviolet range, it is important to know what you plan to do with your reader before purchasing one. Microscopes.com has many spectrophotometers for sale by Thermo, Beckman, and Unico. The ones we currently carry are intended for UV and visible work. The first thing that we would need to know is what wavelength is needed to be read. Anything below about 280-300nm is considered in the UV light range. Most visible specs usually read in the 400-1100 nanometer range, however. It is also important to know how many samples you intend to read in one session. Many current spectrophotometers currently have multi-sample platforms which allows you to read one 'blank' and several samples in a row, without removing your cuvettes from the photometer. Speaking of which, it's extremely important to know what type of cuvette you need for your application. Readings below 250nm require a quartz cuvette. Reading in the upper UV range, however, (260-340nm) can use special plastic cuvettes with UV windows. Readings in the visible range can use disposable cuvettes that are usually very inexpensive to buy.