Sensitivity Deviation
Slope deviations between actual transducer transfer functions and ideal full-scale response lines yield measurement inaccuracies. A span calibration error occurs when the gain factor of an instrument deviates from its specified output per unit input across the full scale range. Unlike zero offsets that shift output values uniformly across all inputs, span errors increase proportionally with applied stimulus magnitude.
Calibration adjustments modify internal amplifier gain or numerical scaling factors to align full-scale output with reference values.
Multi-Point Adjustment
Multi-point calibration sequences measure instrument output at multiple pressure or temperature points across the full operational span. Comparing measured output curves against ideal straight lines identifies gain deviations and non-linearity errors. Software routines update internal multiplication factors to eliminate full-scale sensitivity discrepancies.
Full-Scale Offset
Full-scale calibration errors stem from gain resistor aging, reference voltage drift, or mechanical sensor diaphragm stiffness changes over time. Exposure to pressure spikes above burst limits permanently deforms transducer elements, altering full-scale output sensitivity. Periodic span verification against traceable calibration standards corrects accumulated sensitivity drift.
Calibration Frequency
High-accuracy industrial processes require scheduled full-scale calibration intervals to maintain total loop accuracy within specified tolerances. Documenting span changes across consecutive recalibrations helps establish predictive instrument maintenance schedules.
