Glossary of Spectroscopy Terms - StellarNet, Inc.

What is Spectrometer Accuracy and Precision?

May 25, 2017 | Characterization, Glossary of Spectroscopy Terms

Accuracy is a general term that describes the agreement between a measurement and a true value. Precision is a general term that describes how close measured values are to each other, if they are clustered or spread out. Accuracy is affected by both random and...

What is Spectrometer Time Averaging?

May 25, 2017 | Glossary of Spectroscopy Terms, Software

To increase S/N, several acquisitions can be averaged together. This is called time averaging. Many sources of noise are random, meaning that they cause deviations around a true value. This means that the average is a statistical estimator for the true value. The...

What is a Spectroscopy Blank?

May 25, 2017 | Glossary of Spectroscopy Terms, Sampling

A blank is a sample that contains everything except for the analyte of interest. For example, if you are doing a UV-vis experiment to measure concentrations of Green Fluorescent Protein, the protein has to be dissolved in a solvent. The blank is a sample of just the...

What is Temperature Compensation?

May 25, 2017 | Detectors, Glossary of Spectroscopy Terms

There are 15 “optically black” pixels on StellarNet detectors that are not hit by light during an acquisition. They provide a continuous measurement of the average dark spectrum and can be used to adjust for baseline drift during an experiment. In other words, this...

What is a Stray Light?

May 25, 2017 | Glossary of Spectroscopy Terms, Optics, Spectrograph

Stray light is any light that hits the detector unintentionally. The detector is not able to distinguish wavelengths, so it cannot tell the difference between the e.g. 500 nm light that is supposed to hit a pixel and the 505 nm light that accidentally hit it. It will...

What is Electronic Noise?

May 25, 2017 | Detectors, Glossary of Spectroscopy Terms

Electronic noise is all the noise generated by the electronic circuits after the electrons are converted to a voltage. This includes noise from any amplifiers and the A/D converter. For example, conversions of exactly the same charge will not necessarily yield exactly...