Question

What is the advantage of UV/VIS double-beam instruments over UV/VIS single-beam instruments? What is the advantage of UV/VIS double-beam-in-time instruments over UV/VIS double-beam-in-space instruments?

Answer 1

A single beam system has the beam of light passing through the sample and then passing through the detctors, where as in double beam ther is a beam splitter that splits the beam before it goes into the sample, and the undisturbed beam is then matched with the beam coming out of the sample for error correction

Advantages of Double Beam Systems
->Modern improvements in optics permit high level of automation and offer the same or even better level of detection as compared to earlier single beam systems.
->Instability factors due to lamp drift, stray light, voltage fluctuations do not affect the measurement in real-time.
->Little or no lamp warm up time is required. This not only improves throughput of results but also conserves lamp life

A US/VIS double beam in time instrument will have two beams alternatively sent to the detectro from the unknown sample and known sample, and the detector can read them seperately and compare, where as in space instruments have the detector measure the superposition of the two beams and the components have to be seperated by using mathematics instead for further analysis