Calibration in Hazardous Areas
This article discusses calibration in hazardous areas and what everyone needs to be aware of before entering into a hazardous area with calibration equipment. Other topics covered are the background of flammable and combustible liquids, definition of a hazardous area, the types of relevant industries, the different levels of zones, regulations, equipment classification and various other related practical issues.
There are many different levels of hazardous areas. There are also many different kinds of Ex-rated calibration equipment. A hazardous area is an area (inside or outside) that contains, or may contain, flammable substances. The flammable substance may be a liquid, gas, vapor or dust. The area may contain a flammable substance all of the time, most of the time, or only in specific situations, such as shut-downs or incidents. In such a hazardous area, an explosion or fire is possible if all the three conditions of the so called “explosion triangle” are met. These three conditions are fuel (a flammable substance), source of ignition (or heat) and oxygen (air). The explosion triangle is often presented as triangle, therefore the name.