How do you calibrate a pressure transmitter?

Pressure transmitter calibration involves: applying known pressure inputs (0%, 25%, 50%, 75%, 100% of range using deadweight tester or precision gauge), measuring corresponding output signals (4-20 mA), calculating errors against specifications, and performing zero/span adjustments if needed. HART communicators enable digital trim calibration. A 5-point up-down calibration checks for hysteresis. Document as-found and as-left readings, and verify turndown ratio accuracy if applicable.