Quartz Fibre Filters

The necessity of monitoring emissions on a regular and sometimes permanent basis has inspired the development of a specific set of methods and techniques for the relevant industries. Many of the air quality analysis can be performed with traditional filter papers. However, some analysis requires materials with specific features, for example filters with low metal levels. Many gravimetric methods for the determination of particulate matter in the atmosphere are based on collection onto a high-efficiency or quartz filter. This process involves the collection of airborne particulates by medium or high-volume air sampling, typically over a period of eight hours or longer. The mass of particulate is determined by weighing the filter before and after sampling.

Johnson Test Papers offers a pure range of quartz filters made exclusively with pure quartz (SiO₂) micro-fibres. They are free from binding agents and glass fibre and are subsequently treated thermally to achieve very low levels of heavy metals and trace elements. This eliminates "artefact" products of sulfates and nitrates (from SO₂ and NO₂). High-purity quartz micro-fibre filters are mainly used for the low particle content in air pollution monitoring especially when a very pure filter is required or when the physical or chemical conditions of the gases are extreme.

Our quartz fibres have excellent filtration properties and outstanding weight and dimension stability. They can be used for air sampling and gravimetric calculations in acidic gases, industrial smoke stacks, flues and aerosols, particularly at high temperatures (up to 900ºC) or stronger acid concentration (Expect HF), and for air sampling testing. Quartz filters are suitable for critical analysis and trace level determinations, atomic absorption spectroscopy, and flame emission spectrometry. Its use is also highly recommended when determining the content of heavy metals in the atmosphere.

Properties

Chemical Stability

Excellent chemical stability against acidic gases such as SO₂, HCl,SO₃,SO₄,NO,NO₃ (not HF) with hardly any loss of mass of the filter through possible chemical reactions.

Thermal Stability

Temperature resistant up to 900°C. Resistant to creasing. When using filters in field analysis (high-volume detectors, control of emissions in smokestacks), these filters can be folded for better transport to the laboratory for analysis.

Permeability

Excellent behaviour during the passing of significant volumes of gases, which makes them ideal for use in high-volume detectors.

Retention to Particles

The structure and the physical and chemical properties of quartz micro-fibres are such that these filters have a high level of retention of particles not only on the surface but also in the internal structure of the media.

Our quartz fibres are available in many grades and sizes. Use the contact form for further information.