Everything you need to know about calibration

Introduction to calibration

When equipment is used to measure materials or product, it must be accurate. To ensure this, the equipment must be calibrated and then checked for accuracy.

Contents

• The standards.
• The requirements.
• BRCGS Food Safety Issue 9.
• Useful links.

The standards

This article on laboratory controls is written to meet the following sections of the standards:

The requirements

Procedure

Procedures must ensure that measuring equipment, is accurate.

The procedure must include:

• Calibration and adjustment to a set standard where needed.
• Checks to ensure accuracy, to agreed parameters at a set frequency.

Measuring equipment

In-line and off-line measuring equipment, including robotic sensors, used to monitor product safety, quality and legality must be controlled.

There must be annual calibration of detection equipment.

Magnets, where present, are tested for strength on a defined frequency. Deviations from manufacturer requirements or specifications are addressed.

Certificates

Calibration certificates and records must be available and up to date and state the acceptable equipment tolerance.

Risk assessment

These devices must be calibrated based on risk assessment, which include:

• Legislation requirements.
• Equipment manufacturer’s recommendations.
• The purpose of the measurement, for example, legal, safety, validation etc.

Log

A measuring equipment log must be in place which:

• Lists of all measuring equipment and its location.
• Records the equipment identification code, which is also visible on the equipment.
• Details the frequency of calibration and the next calibration due date.

Equipment specification

Measuring equipment used for checks of finished product quantity and packaging tare checks must be fit for the purpose. The equipment must:

• Comply with local legalisation.
• Be suitable for the operational environment where they’re located.
• Measure to an accuracy, and be calibrated to a range, that’s suitable for the products being measured.

Assessment

The calibration and accuracy checks must:

• Follow methods which are traceable to a recognised national or international standard where possible.
• Where this isn’t possible the method must be validation.
• Be carried out at a frequency determined through risk assessment.
• Be carried out at a frequency that takes into account the consequence of failure.

Validation

Where equipment is used for validation, its inaccuracy and acceptable parameters, must be taken into consideration when determining critical limits.

Unauthorised access

Measuring equipment must be:

• Secured to prevent it from being adjusted by unauthorised staff.
• Protected so that it doesn’t deteriorate, get damaged or mis-used.

Accuracy checks

Accuracy checks must:

• Be carried out to a set frequency, which has been determined through risk assessment.
• Have defined acceptable parameters, which are relative to the parameters being measured.
• Be carried out and recorded, by authorised and trained staff, following set procedures.
• Be traceable back to the national standard.

Corrective action and root cause

When measuring equipment is found to be inaccurate during calibration or accuracy checks, corrective action must include the following:

• Equipment must be taken out of service, replaced or repaired.
• The incident procedure must be applied, where the product produced may be unsafe or illegal.
• Affected product must be quarantined and reinspected.
• Product may only be released for sale when approved by a Decision Maker.

Preventive action must also be taken (determined using root cause analysis), where the failure has impacted product or where a trend is identified.

Frequency of automated equipment checks

Automated equipment must be checked at least:

• At the start of the production run.
• At the end of the production run.
• At a frequency which means that when the check is out of spec, any effected product will still be in the sites control and can be brought back.

Competency

Calibration must be carried out by:

• A specialist contractor.
• Staff who have completed specialist training.

Useful links

Magnet testing and standards (Magnetshop.com): Magnet Testing | Permanent Magnet Guidelines & Standards (magnetshop.com)