{"id":12429,"date":"2023-12-05T08:00:26","date_gmt":"2023-12-05T08:00:26","guid":{"rendered":"https:\/\/www.thermofisher.com\/blog\/metals\/?p=12429"},"modified":"2026-02-03T20:46:23","modified_gmt":"2026-02-03T20:46:23","slug":"reference-materials-are-essential-to-determine-uncertainty-in-measurement-for-spark-spectrometry","status":"publish","type":"post","link":"https:\/\/www.thermofisher.com\/blog\/metals\/reference-materials-are-essential-to-determine-uncertainty-in-measurement-for-spark-spectrometry\/","title":{"rendered":"Reference Materials Are Essential to Determine Uncertainty in Measurement for Spark Spectrometry"},"content":{"rendered":"

Every measurement comes with uncertainty. If you\u2019re measuring with a ruler that is only marked to the millimeter, or a with balance using only one-gram standard weights, there is going to be some point at which that measurement becomes inexact. You can get pretty close to exact, but the question is, how close? How certain can you be that your measurement is correct? This calculation of the uncertainty in measurement is where reference materials play a key role, especially in a field as specific as spark spectrometry.<\/span>\u00a0<\/span><\/p>\n

Spark spectrometers<\/a> (also referred to as spark emission spectrometers or spark OES) analyze metallic samples through the application of an electric arc or spark, causing analytes to emit light and thereby reveal their presence and concentration via distinctive wavelength signatures. Spark spectrometers are relatively easy to use and maintain, and they provide the fastest determination of present elements with high accuracy and precision. But <\/span>how<\/span><\/i> accurate and precise they are, is a question that needs to be answered, for each and every measurement performed.<\/span>\u00a0<\/span><\/p>\n

With <\/span>spark spectrometry of metals<\/a>\u00a0knowledge of the level of uncertainty in measurement is hugely important, and is necessary to properly validate measurement results. According to DIN EN ISO 17025,<\/span> the worldwide standard for laboratory accreditation in the area of testing and calibration, it is necessary to calculate the measurement uncertainty for each measurement result.<\/span>\u00a0<\/span><\/p>\n

Uncertainty in measurement for reference materials<\/span>\u00a0<\/span><\/h2>\n

Uncertainty is generally defined as a range of values centered on the measurement value, and it includes an asserted true value with the stated probability. [To put it in more technical terms, according to the Guide to the Expression of Uncertainty in Measurement (GUM) and the International Vocabulary of Metrology (VIM), the uncertainty of measurement is a measure of the dispersion of values that can reasonably be attributed to a measurement result. The parameter of uncertainty is specifically associated with the result of a measurement.]\u00a0<\/span>\u00a0<\/span><\/p>\n

Like most analytical instrumentation, spark spectrometry is comparative, meaning that it requires a sample of a known composition for accurate calibration. These known samples are called reference materials, and measurements of unknown samples can be compared to them. Uncertainty in measurement for reference materials needs to be accounted for and applied to measurements of unknowns. For this reason, it is important to understand what type of reference materials might be in use for any given experiment.<\/span>\u00a0<\/span><\/p>\n

Spark spectrometry reference materials<\/span>\u00a0<\/span><\/h2>\n

Four types of reference materials can be used for spark spectrometry: Setting Up samples, reference materials (RMs), Certified reference materials (CRMs), and Traceable CRMs.<\/span>\u00a0<\/span><\/p>\n