Calibration Best Practices (Field Proven)

Calibration does not fix unstable analyzers. This guide explains when to calibrate, when NOT to calibrate, and how to avoid false drift.

Golden rule: Never calibrate during alarms, instability, or abnormal process conditions.

Before Calibration (Mandatory)

  • No active flow, pressure, or system alarms
  • Stable readings for at least 30–60 minutes
  • Correct calibration gas connected
  • Sample system verified dry and leak-free

Calibration Gas Handling

  • Use certified gas with valid expiry date
  • Confirm gas concentration matches analyzer range
  • Do not reuse partially empty cylinders
  • Use proper regulators (no needle valves)

Zero & Span Application

  • Allow full stabilization time (never rush)
  • Confirm zero returns correctly after span
  • Do not “chase” readings with repeated adjustments

Verification (Most Skipped Step)

  • Apply verification gas after calibration
  • Confirm result within acceptance limits
  • Document results before returning to process

Common Calibration Mistakes

  • Calibrating during pressure hunting
  • Ignoring moisture in sample lines
  • Using wrong gas or wrong concentration
  • Blaming sensor instead of sampling
Field truth: Most “drift” complaints are caused by unstable sampling — not sensor ageing.