Set food industry calibration schedules by risk, keep traceable records, and prepare for ISO/IEC 17025 and FSSC 22000 audits with on site choices.
A formal, traceable calibration programme is the control that keeps food safety measurements accurate, auditable and defensible. It ties every thermometer, scale and analyser to a known reference, so your records stand up to ISO/IEC 17025 expectations, NATA-accredited evidence and FSSC 22000 audits. Start with a device inventory, rank each instrument by risk, and book an accredited provider such as PCS Precision.
TL;DR:
- Daily ice point checks on critical handheld thermometers catch shifts, but they do not replace formal calibration across the instrument’s working range.
- Choose a laboratory whose accredited scope covers each parameter and range, and require certificates to show uncertainty, traceability, and results before and after adjustment.
- Scales used in trade also require verification under Australia’s National Measurement Institute framework; calibration alone does not satisfy that legal requirement.
- Set formal intervals by risk and drift history, then recalibrate after a drop, repair, failed check, or process change and assess affected product.
Every critical limit in your HACCP plan rests on a measurement. If the thermometer reading a cook step is out by a few degrees, the control looks fine on paper while the product is not. The same logic applies to a checkweigher that lets underweight packs through or a pH meter that drifts during a batch release test. Inaccurate instruments produce failed controls, doubtful records, product safety incidents, recalls and non-conformances at audit.
Calibration fixes this by comparing your instrument against a reference of known accuracy and documenting the result. That record is what an auditor wants to see. Under FSSC 22000, laboratory analysis of parameters critical to food safety should be carried out by a competent laboratory operating in accordance with ISO/IEC 17025, with monitoring through proficiency testing.
When you assess a calibration provider, look for these trust signals:
FSSC 22000 states that laboratory analyses used to verify parameters critical to food safety should be performed by laboratories working to ISO/IEC 17025 requirements. In practice, that means your calibration evidence is part of your certification case, not an optional extra.
Start with the devices that sit closest to a critical control point, then work outwards to quality and process instruments. A practical priority list looks like this:
Keep two layers separate. A daily functional check, such as a quick ice-point test on a probe or a check weight on a scale, confirms the device is behaving today. A scheduled formal calibration, performed against traceable standards, proves it is accurate over its whole working range. One does not replace the other.
Pro Tip: Give every critical handheld thermometer a daily ice-point check logged by the operator, and treat any shift beyond your acceptance limit as a trigger for immediate formal recalibration.
A programme works when it is simple enough to run every week and rigorous enough to survive an audit. We recommend this sequence:
Each certificate or report should show:
For frequency, combine daily functional checks on critical handheld devices, periodic formal calibration set by risk, and event-driven recalibration after a drop, repair, failed check or process change. Our guide to why regular calibration is critical for industrial accuracy explains how drift builds up between intervals.
Three names come up in almost every audit conversation. ISO/IEC 17025 sets the competence requirements for testing and calibration laboratories, and FSSC 22000 points to it when laboratory analysis supports food safety decisions. NATA is Australia’s national accreditation body, and a NATA-accredited laboratory has had its technical competence assessed against that standard. We explain how the scope works in our article on NATA calibration standards.
Verification is a separate matter. In Australia, weighing instruments used for trade must be verified under the National Measurement Institute framework, and NMI verifier training for non-automatic weighing instruments can take less than three hours. The NMI e-learning course covers the tests a verifier performs: repeatability, eccentricity, zero-setting and the weighing test, plus completing a test report.
When you review a certificate, check:
NMI states that its non-automatic weighing instrument course runs less than three hours, while specialised verifier courses are typically one day. That gives you a realistic benchmark when you plan verifier competence in-house.
On-site calibration suits most process instruments. The device stays in its working environment, production loses less time, and we can test it under the conditions it actually sees. In-laboratory calibration gives controlled temperature and humidity, a wider scope and lower uncertainty, which is the better choice for reference thermometers, check weights and high-resolution balances.
Traceability is what separates a calibration from a comparison. A proper report shows the reference standards used, their own calibration status and the measurement uncertainty achieved, so the chain runs back to national standards without a gap. Our traceable metrology and NATA metrology pages show how that chain is documented.
Practical points that help you choose:
A programme that is never reviewed slowly drifts out of line with the plant. Set an annual review, and trigger an extra one after any recall, major audit finding or line change. The review asks one question: does the evidence show that every critical measurement was accurate when it was used?
Work through these checks:
Verification also covers people. Operators who run daily checks need a clear procedure, a reference point such as an ice bath or check weight, and a record sheet. For weighing, we point teams to our audit-ready balance calibration procedure, which you can adapt as a checklist. For laboratory work, a periodic proficiency test or inter-laboratory comparison shows whether your results hold up against peers, which is the same logic FSSC 22000 applies to laboratory competence.
Finally, close the loop with management. Report the number of out-of-tolerance findings, overdue items and corrective actions at your food safety team meeting, so calibration is treated as a control rather than an administrative chore.
Most failures are about process, not technology. The usual pitfalls are predictable:
Boiling-point checks also depend on local conditions, so record the method and any correction you apply. When a check fails, remove the device from service, tag it, and investigate before it goes back to the line. Supply chains add another layer: if you import ingredients and rely on supplier weights or temperature records, a guide such as this step-by-step importing food products overview is a useful reminder that measurement and documentation control continues beyond your own site.
Quality and shelf life are built from small measurements repeated over time. A chiller running warmer than the display shows, a pH reading that is slightly high, or a moisture analyser that underreads can each move a product outside its intended window without anyone noticing.
Consider the mechanisms:
The commercial effect is just as real. Consistent measurements reduce rework, rejected batches and complaints, and they give your technical team confidence when they extend or tighten a shelf life claim. If your shelf life study used an uncalibrated chamber or analyser, the result is difficult to defend. Calibrating the instruments behind those studies turns shelf life from an estimate into evidence.
Each device class has its own method, but the structure is the same: stabilise, compare against a traceable reference, record as-found, adjust if needed, then record as-left.
Thermometers and probes. Compare against a calibrated reference thermometer in a stirred bath or dry-block at points covering your working range, typically including ice point and your critical limits. Allow time for the probe to settle and immerse it to the correct depth. Check that probe tips, cables and displays are undamaged.
Data loggers. Calibrate the sensor and the logger together, at several temperatures, and confirm the clock and sampling interval. Verify alarm set points as well as the readings.
Balances and scales. Level the instrument, warm it up and run repeatability, eccentricity and linearity tests using traceable weights. These are the same tests described in the NMI verification course material, and we outline a worked procedure in our balance calibration guide. For lab-grade work, see our microbalance calibration SOP.
pH meters. Use fresh buffers that bracket your samples, apply multi-point calibration, and record slope and offset. A poor slope signals a tired electrode, not just a drifting meter.
Moisture analysers. Check the balance first, then the heating element temperature, then a reference material with known moisture content.
Metal detectors and X-ray systems. Challenge the system with certified test pieces at the product’s real position and speed, confirm rejection and fail-safe alarms, and document sensitivity results by product.
Whatever the device, keep the procedure written, controlled and available to the technician performing it.
Costs depend on the number and type of instruments, how often they are calibrated, whether work is on-site or in the laboratory, and whether you need accredited or traceable certificates. We publish no standard prices for these services, so pricing for your site is available on request through a quote.
A sensible budget has several parts:
Several choices lower cost without lowering control. Rationalise the inventory so that low-risk devices are not treated like critical ones. Standardise on fewer instrument models, which simplifies procedures and spares. Bundle on-site work into a single visit, and use preventative maintenance to catch faults before they cause failed calibrations.
Weigh the spend against the alternative. A single recall, rejected consignment or major audit finding usually costs far more than a year of well-run calibration. Budget for the programme as insurance for the evidence your business relies on.
Teams often jump straight to a calendar of due dates. We think that is the wrong order. A schedule built on an incomplete inventory is a tidy record of the wrong things. Walk the floor, list every instrument that touches a critical limit, and only then decide intervals. Our multi-brand experience across scales, thermometers, analysers and loadcells shows that gaps usually sit in the humble handheld devices.
Your next steps are to complete the device inventory, set risk-based intervals with clear acceptance limits, and arrange a programme review with an accredited provider. If it helps, we can walk through your current records.
— Kaz
We give food businesses calibration they can put in front of an auditor. PCS Precision is NATA accredited and certified to a quality management standard, and we work across multiple equipment brands regardless of where you bought the instrument.
Request a sample report or a quote through our calibration services page, or browse the equipment we sell if an instrument needs replacing.
Yes. Level the scale, let it warm up, then test it with certified check weights across its range, including repeatability and off-centre loading. For scales used in trade, verification under the National Measurement Institute framework applies, and an accredited provider can perform and document both.
It means checking and adjusting an instrument at four reference points across its range, rather than one or two. It is common for pH meters and temperature devices, because four points reveal non-linearity that a single check would miss.
It sits mainly under quality assurance, because it proves the measuring system is reliable before it is used. The checks you run on product with those instruments are quality control, and they depend on the calibration being sound.
Its purpose is to show that an instrument reads correctly against a known reference, within a stated uncertainty. For food businesses, that provides trustworthy data for critical limits and the traceable records auditors expect.
