Wolfson Electrostatics
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New instruments for electrostatic hazard assessment
The growing threat posed by uncontrolled static electricity in the chemical and pharmaceutical industries is recognised in many international standards. These standards give clear guidelines on the properties of materials for use in the presence of sensitive flammable vapours and dusts. The key parameters determining the suitability of such materials are electrical resistivity and charge decay. For example, British Standard 5958 recommends an upper resistivity limit of 1011 Ohms for drum liners when handling dry or solvent-wet powders.
Wolfson Electrostatics has now developed two new instruments, which enable these two key parameters to be directly measured. Both instruments are designed to conform to the test methods described in BS 7506.
The resistivity meter (pictured) enables a direct reading of surface resistivity in Ohms/square on a variety of items such as drums, liners, gloves, clothing and flooring. An accessory for the measurement of powders and granular materials is also available as an optional extra. The resistivity meter covers the range 105 to 1013 Ohms and can be operated from both mains and integral rechargeable batteries.
The electrostatic charge decay meter is designed primarily for packaging materials and liners but can also be used to determine the static dissipative qualities of clothing, gloves and even floor tiles. The instrument works by applying an electrostatic potential of up to 5000 volts to the sample under test. The sample is then grounded and the surface potential monitored using an electric field meter.
Both instruments are now commercially available and are ideally suited to on-site operation. For further information on all electrostatic measurement requirements contact Wolfson Electrostatics.