Pressure calibration can be challenging in the best of environments. Working in an area that has the potential for explosion takes the degree of difficulty to another level - one where the technician needs proper training and equipment.
To conduct pressure calibrations in potentially explosive environments, you need a pressure calibrator that is certified as intrinsically safe. Devices certified as "intrinsically safe" are designed to be unable to release sufficient energy, by either thermal or electrical means, to cause ignition of flammable material (gas, dust/particulates).
Intrinsic safety is particularly important for technicians working in the petrochemical and pharmaceutical industries, around bulk materials such as grain, in mining, or in any environment where explosive gases are present. The importance of safety in these environments can't be stressed enough. It takes a very small amount of energy to cause an ignition. For example, igniting a mixture of hydrogen in air requires only 20 uJ of energy. Following required safety practices and using specially engineered intrinsically safe tools (such as the Fluke 718Ex Intrinsically Safe Pressure Calibrator) reduces the inherent risks involved in working working around these hazards.
Typical pressure applications include calibrating a P/I transmitter in a classified location and calibrating a pressure switch in a classified area.