Hazardous area classification, explained
Zones, divisions, gas groups and temperature classes decide which equipment may sit in a classified area. IP and NEMA ratings answer a different question.
HAZOP
Guideword-based study of process hazards and deviations.
Hazard and Operability Study: a facilitated, guideword-based review of process deviations such as more pressure, less flow, or reverse flow, their causes and consequences, and required safeguards.
See also: Safety instrumented system (SIS) · Management of change (MOC) · Safety instrumented function (SIF)
Use the concept: 4–20 mA loop scaling · Compressed air leak cost calculator · Engineering unit converter
In depth
PLC analog input scaling: raw counts, 4–20 mA and diagnostics
Map raw counts into engineering units, check the configured channel range, and keep signal-quality diagnostics separate from the displayed value.
Compressed air leak cost: turn flow estimates into verified savings
Calculate a leak energy equivalent, keep free-air reference conditions consistent, and check compressor response before promising a saving.