Calibration Deep Dive

A thermometer used for food preparation and storage is required by HACCP to be calibrated.

A thermometer is calibrated by measurements at a series of temperature-fixed points (freezing/melting points, triple points, or vapor pressure points of pure materials). By using this method we insert the thermometer in a fixed point cell which provides the desired temperature point.

Why should you calibrate your thermometer?

  • Standardization & Repeatability in measurements
  • Establish the reliability of the instrument with a calibration
  • Assurance you have a maintained accurate reading
  • In general, the accuracy of a thermometer drifts over time and therefore accurate readings can’t be guaranteed.
  • The accuracy drifts on a thermometer because of mechanical shock and extreme temperatures
  • Without regular calibration, the equipment can fall out of spec, providing you with inaccurate measurements. This threatens quality, safety, and overall equipment longevity

PM Instrumentation uses a SANAS Accredited Temperature Calibration Company for all customer calibrations.

When should you calibrate your thermometer?

  • Before use, a brand-new thermometer needs to be SANAS calibrated, unless provided with a manufacturer’s certificate of calibration.
  • When a thermometer has been dropped
  • After long storage, the time has passed without use.
  • When a thermometer is used in different temperature zones – kitchen vs freezer, verification may be necessary.

What are the Legal requirements for Food Chain Audits with the FSSC 22000 [Food Safety System Certification]?

In April 2023 the new requirements for Organizations to be audited released the following:
The new Version 6 introduces changes in product categories, realignment of food chain categories, and integration of food safety and quality culture requirements.

Companies already certified have until April 1, 2024, to prepare. All certification audits from that date onwards will be to FSSC 22000 Version 6. The transition window is a 12-month transition window, meaning that all upgrade audits must be completed before 31 March 2025. Specific rules apply for those with audit days bridging March and April 2024 in terms of what Version may be applied to the different stages of the audit.  Our recommendation is that companies with existing certificate start preparations as early as possible and plan to implement all requirements in line with the upgraded Version 6


Management of services and purchased materials [All Food Chain Categories] The organization shall ensure that where laboratory analysis services are used for the verification and/or validation of food safety these shall be conducted by a competent laboratory [including both internal and external laboratories as applicable] that has the capability to produce precise and repeatable tests results using validated test methods and best practices [eg. successful participation in proficiency testing programs, regulatory-approved programs, or accreditation to international standards such as ISO 17025.

When can’t a thermometer be calibrated?

A thermometer can only be calibrated when it is in working order. If your thermometer has a detached probe or exposed wires it is not fit for calibration and a replacement or repair is required.

How long will it take to get my thermometer calibrated?

7 – 10 working days

Give us a ring to book your thermometer in for calibration +27 11 728 6099.

Updated 14 June 2023