Serinus Gas Analyzer

Sulfur Dioxide background

Sulfur Dioxide is the product of the combustion of sulfur compounds and causes significant environmental pollution. The main source of Sulfur Dioxide in the environment are from various industrial processes such as the burning of coal in power stations, the extraction of metals from ore and combustion of fuel within automobiles. Sulfur dioxide is a noxious gas that can cause respiratory damage as well as impairing visibility when in high concentrations. Sulfur Dioxide also has the potential to form Acid rain (H2SO4) which causes health, environmental and infrastructural problems to human society.

Sulfur Dioxide measurement The measurement of sulfur dioxide is based on classical fluorescence spectroscopy principles. Sulfur dioxide (SO2) exhibits a strong ultraviolet (UV) absorption spectrum between 200 and 240nm, when Sulfur Dioxide absorbs UV from this, emission of photons occurs (300-400nm). The amount of fluorescence emitted is directly proportional to the Sulfur Dioxide concentration.   The Serinus 50 follows these principles and measurement techniques:

• Sample air is passed through a hydrocarbon kicker which removes hydrocarbons in high concentration in sample air to low hydrocarbon concentration exhaust airA zinc discharge lamp and a UV bandpass filter are used to produce radiation at 214nm.
• The radiation (214nm) is focused into the fluorescence cell where it interacts with Sulfur Dioxide molecules and emits photons uniformly in all directions
• A portion of the fluorescence is collected and filtered
• Wavelengths at 310-350nm pass through the filter where they reach the photomultiplier and record a signal
• A reference detector monitors the emission from the zinc lamp and is used to correct for fluctuations in lamp intensity
• Exhaust air is scrubbed with a charcoal scrubber to eliminate Hydrocarbons and SO₂. This air is then ideal for use in the hydrocarbon kicker to remove hydrocarbons from sample air.

Sulfur Dioxide analyzer measurement

The Serinus 50 Sulfur Dioxide analyzer uses UV fluorescent radiation technology to detect Sulfur Dioxide to a sensitivity of 0.4 ppb in the range of 0-20 ppm. The Serinus 50 measures Sulfur Dioxide with the following instruments/techniques: Hydrocarbon kicker UV lamp Fluorescence cell Optical bandpass filters Photomultiplier tube (PMT)

The SO₂ concentration is automatically corrected for gas temperature and pressure changes and referenced to 0°C, 20°C or 25°C at 1 atmosphere. This allows the Serinus 50 to sample in the most useful range of Sulfur Dioxide ambient measurement (25-500 ppb Sulfur Dioxide in air).