Calibration Terms and Strategy

1. Introduction

Calibration plays a critical role in ensuring the accuracy, reliability, and traceability of measurement instruments used across industries such as healthcare, pharmaceuticals, data centres, oil & gas, and advanced manufacturing. At PowerQ AnalytiQ, calibration is not viewed as a standalone task but as part of an integrated Testing & Commissioning (T&C) strategy, aligning with global standards such as ISO/IEC 17025, ISO 9001, and SAC-SINGLAS requirements.

This white paper outlines the calibration philosophy, scope, procedures, and responsibilities applied in large-scale projects. It provides a framework that ensures every instrument contributes to system integrity, compliance, and operational performance.

2. Calibration Philosophy

• Calibration confirms that an instrument’s readings reflect true physical values.
• Instruments are categorized based on Critical Instrument Assessment (CIA) into GMP-critical, safety-critical, operational, or indication-only.
• All calibrations are performed using traceable standards by qualified technicians, ensuring results are globally recognized through Mutual Recognition Arrangements (MRAs).
• By embedding calibration within the commissioning cycle, PowerQ AnalytiQ ensures full confidence in operational outcomes.

3. Calibration Strategy

3.1 Objectives

• Define calibration deliverables early in the project.
• Reduce project risk, cost, and schedule delays.
• Standardize calibration practices across contractors and systems.
• Maintain transparency with robust documentation and traceability.

3.2 Scope

Applies to all pressure, temperature, flow, electrical, and Building Management System (BMS) instruments, including:

• Gauges, transmitters, and calibrators
• Temperature probes, sensors, dataloggers
• Airflow and velocity meters
• Electrical test devices and analyzers
• IAQ monitors and energy meters

3.3 Execution

• System-by-system Mechanical Completion (MC): Each instrument is verified and tested as part of MC.
• Calibration Pathways: Depending on CIA category, instruments undergo bench calibration, field calibration, or validation through vendor skid certificates.
• Verification & Loop Checks: All safety-critical and GMP instruments undergo loop simulations and function checks before commissioning.

4. Calibration Categories

5. Calibration Requirements

Before calibration, identify instrument type, specs, range, fittings, tools, and reference tables. Notify all parties and ensure work permit approval. Calibration equipment must have valid (≤1 year) traceable certification and meet a 4:1 accuracy ratio to the instrument under test, with details recorded on result sheets.

• Skid-Built Instruments: Supplied as part of vendor packages, must include valid factory calibration certificates.
• Stick-Built Instruments: Delivered separately and calibrated on-site or in the lab.
• Every instrument must carry a valid calibration certificate before commissioning or qualification activities.
• Stickers are applied for traceability:
  • Green = factory certificate
  • Blue = bench calibration
  • Orange = field calibration

result sheets

6. Roles & Responsibilities

• Project C&Q Manager – Oversee calibration planning, execution, and compliance.
• Construction Contractor – Deliver instruments with valid certificates, maintain datasheets and indexes.
• PowerQ AnalytiQ (Calibration Contractor) – Perform bench/field calibration, provide certified equipment, issue certificates.
• Client / End-User QA/QC – Approve calibration requirements, perform CAT1 verification, take final handover of certificates.
• Validation Team – Review certificates for GMP-critical instruments to support qualification and regulatory compliance.
• 7. Handover & Documentation

  Handover is executed on a system-by-system basis, supported by structured dossiers:

  • SMCD (System Mechanical Completion Dossier) – Construction deliverables, calibration certificates for CAT2/3.
  • SCCD (System Commissioning Completion Dossier) – Commissioning documents and CAT1/CAT2A certificates.
  • SQCD (System Qualification Completion Dossier) – Qualification records and GMP validation-ready certificates.

  All dossiers are designed to ensure audit readiness and regulatory compliance.

• Quality & Compliance

• PowerQ AnalytiQ’s calibration framework is anchored on:

  • SAC-SINGLAS ISO/IEC 17025 – Laboratory competence & technical accuracy
  • ISO 9001 – Quality management and continuous improvement
  • BizSAFE Star – Commitment to workplace safety and reliability

  We define instrument scope and criticality, prepare with proper specs and permits, and use certified traceable standards (4:1 accuracy). Calibration is executed in-lab or on-site, with results fully documented and third party audited to ISO 9001 & ISO/IEC 17025. Continuous improvement ensures compliance, reliability, and efficiency

  These accreditations ensure our calibration services meet the highest benchmarks of precision, reliability, and global recognition.

• 8. Common Calibration Errors and Solutions

  8.1 Error When Reversing the Range

  In DP level applications, reversing the range (e.g., from -87 to -1 mbar → -1 to -87 mbar) often leads to rejection by the transmitter if limits are incorrectly set.
  Solution: Always insert an intermediate value before finalizing reversal (e.g., LRV to -40 → URV to -87 → LRV to -1).

• 8.2 4–20 mA Range Mismatch

  When transmitter ranges do not match the DCS or HMI configuration, erroneous readings occur.
  Solution: Ensure range changes are always documented and verified against the control system.

  8.3 Corrupting the Range to Make 4–20 mA Right

  A frequent mistake is using “zero” or “set PV LRV” adjustments instead of correctly setting the range. This can mask problems, creating mismatches.
  Correct Practice: Always set the range through proper device configuration rather than force-adjusting outputs.

• 8.4 Sensor Reading Corruption

  Using zero-trim to cancel wet-leg errors leads to hidden offsets.Correct Practice: Cancel the leg correctly by setting the appropriate range.

• 8.5 Non-Interactive Zero and Span

  Modern transmitters allow independent zero and span adjustment.

  • If the lower range value is shifted, the span remains constant.
  • If the upper range value is shifted, only the upper end changes, maintaining the zero point.

  This improves flexibility but requires precise understanding by technicians to avoid errors.

  9. Comprehensive Calibration Management

  We  offers site-wide calibration management beyond just performing calibrations. Our service ensures that every instrument, regardless of type or location, is kept within compliance:

  • On-site calibration – Performed where possible, minimizing downtime.
  • Third-party calibration support – If an instrument cannot be calibrated on-site or requires OEM expertise or restrictions, we manage the logistics by sending it to accredited external party.
  • Consolidation & tracking – All calibration activities, whether done internally or externally, are consolidated into a single certificate database for traceability.
  • Reinstallation & verification – Instruments sent out are re-installed and functionally checked on-site to ensure they operate correctly after calibration.
  • Lifecycle coordination – We manage calibration schedules, reminders, and compliance audits to reduce administrative burden for our clients.

  This integrated approach means clients only need to liaise with one partner—PowerQ—while we handle the full calibration chain.

• 10. Conclusion

  Calibration is more than compliance—it is about ensuring operational excellence, safety, and reliability. At PowerQ AnalytiQ, we provide a structured, internationally recognized calibration framework that prevents errors, ensures confidence, and supports long-term asset performance.

  Our scope of services includes:

  • Instruments Calibration, Testing & Analysis
  • On-site Calibration & Troubleshooting
  • Instruments Repair & Health Checks
  • Instrumentation System Audits
  • Control Valve Servicing & Maintenance
  • Rental of Test Instruments