Trending Emissions Monitoring Bengt Löfstedt General, AQM, CEM 2024-01-02 View Count 1773 For the past year, OPSIS has received many orders for equipment for the monitoring of the concentrations of total mercury and dioxins in emissions to air, primarily from waste-to-energy facilities. What brought this along? Read More »
Air Pollution Part 4 – Reduction Methods Bengt Löfstedt General, AQM, CEM 2023-12-07 View Count 1306 Air pollution is undesirable but there are ways to fight it. We wrap up the series of articles about air pollution by taking a look at what to do about it. Read More »
Air Pollution Part 3 – Sources of Particulates Bengt Löfstedt General, AQM, CEM 2023-11-30 View Count 1506 In this article, we take a closer look at how particulate matter is generated, with emphasis on the smallest fractions which also are the ones with the worst health effects. Read More »
Air Pollution Part 2 – Sources of Gaseous Substances Bengt Löfstedt General, AQM, CEM 2023-11-23 View Count 1529 We continue the series of articles on air pollution by taking a closer look at where gas-phase air pollution comes from. Read More »
Air Pollution Part 1 – What’s in the Air? Bengt Löfstedt General, AQM, CEM 2023-11-16 View Count 1325 What is air pollution, where does it come from, and what can we do about it? This article is a first in a short series addressing these topics. Read More »
Gas Concentration Units and Unit Conversions Bengt Löfstedt General, AQM, CEM 2023-05-11 View Count 2722 On the most fundamental level, the signal from the sensor of a gas analyser gives the number of gas molecules, usually along an optical light beam or in a certain sampling volume. However, a concentration should not be expressed in number of molecules – the number would be far too big. Instead, it is scaled to a unit of weight-per-cubic-metre or volumetric share. How is the scaling done? Read More »
Uncertainties in Measurements Bengt Löfstedt General, AQM, CEM 2023-04-20 View Count 2063 With all efforts made on precision instrumentation, quality assurance, calibrations, parallel measurements, and adjustments, the measurement results produced by a gas monitor should be spot on, right? Well, not quite… Read More »
Instrument Interfaces Bengt Löfstedt AQM, CEM, General 2023-04-06 View Count 1698 A lot of efforts are usually spent on gas concentration measurements and making sure that the measurements are correct. However, all that is of little value if the resulting data is not available. Here is where the instrument interfaces come in play. Read More »
Spring is in the Air Bengt Löfstedt General 2023-03-16 View Count 1895 At the home of OPSIS, the phrase ‘spring is in the air’ is an established saying which means long-awaited warmer and longer days and the sense of a new beginning. But what’s in the air in the spring, really? Let’s take a look at seasonal variations of air pollution! Read More »
Good Averages, on Average? Bengt Löfstedt General 2023-03-13 View Count 1824 We all know how to calculate the average of a set of values: add the individual values and then divide by the number of them. Right? Yes, almost always right, but if you work with air quality and specifically meteorological data, you must sometimes think a little further. Read More »