Posted by: chrisball | Posted on: May 7th, 2012 | 1 Comments
When measuring the concentration of mercury within a sample it is important to understand the effect of different measurement units on the accuracy of the results. When looking at gas phase mercury concentrations there are a wide range of different units encountered including pg/l, ng/l, ppm, ppb and more. Unfortunately all of these units are ambiguous without more detailed information about how they are created.
As we are looking at mercury in gas samples, when we are measuring mass volume units it is important to look at specific factors that will effect the gas measurement such as the temperature and pressure of the gas. There are a number of factors that can affect the measurement basis, such as the contract requirements or the standard being followed.
Simply altering the measurement temperature from 0c to 20c will affect the measurement result by approximately 7%, which can be highly significant in certain environments.
With measurements of PPM and PPB, the variance can be significantly higher, depending on the measurement basis. Whether you are measuring mass/mass, mass/volume or volume/volume can result in differences of up to 1000 times.
In this video we investigate the factors that are important to ensure that your measurements are accurate.