Hazardous Locations Safety Handbook
This BLH handbook is intended to educate the user regarding the proper selection ofelectronic weighing systems used in hazardous locations. This document does not cover the installation of equipment as this is typically the responsibility of the installing electrician and/ or engineering design ﬁrm. Information contained herein has been compiled from a number of published sources and condensed to cover the subject as related to electronic weighing equipment only.
The stated purpose of the (NEC) code is 'the practical safeguarding of persons and property from hazards arising from the use of electricity'. Articles 500 through 517 of the code cover the installation of electrical equipment in locations where ﬁre or explosion hazards may exist due to ﬂammable gases or vapors, ﬂammable liquids, combustible dust, or ignitable ﬁbers
The classiﬁcation of hazardous areas is dependent upon the properties of various hazardous materials and the likelihood of their presence.
The auto ignition temperature (AIT) of a hazard is a consideration when specifying equipment. A system of marking the external surface temperature of equipment for hazardous areas exists to identify suitability for a particular application. The following chart lists the temperature ranges for the various ratings. NFPA standard 497M provides information of the ignition temperatures for Class I and Class II materials.
Download this guide to safe electronic weighing in hazardous locations. Get information on calibration methods and procedures too.