Thermometer Calibration in NZ: The Check Is Required, the Results Log Is Optional

Do you have to keep thermometer calibration records in NZ?

Yes and no — and the split matters. MPI's Record keeping guidance (February 2026) lists equipment and facilities maintenance — including calibrating your own thermometer — as a mandatory record for Simply Safe & Suitable template businesses. The same guidance's record table then says it is optional to record the results of the thermometer calibration. Doing the calibration, and noting it in your maintenance record, is the required part; the column of readings is not.

Why be this precise? Because a lot of calibration advice written for other countries — or written to sell services — treats a full results log as legally required. For NZ template-plan businesses, MPI's February 2026 guidance is the document that settles it.

How to calibrate a food thermometer — MPI's method

The Simply Safe & Suitable template's "Managing places and equipment" card points operators to MPI's own thermometer calibration guidance as its worked example (SS&S template, Dark Blue Card). That guidance — which likens calibration to a WOF for your thermometer — gives three ways to check yours:

Two details from the same MPI guidance that make the check valid: don't let the probe touch the sides or bottom of the container, and hold it in place for 10 seconds before reading.

If your thermometer reads outside those ranges, treat its readings as unreliable until it's fixed: adjust it following the manufacturer's instructions (many probe thermometers have a reset or calibration screw) or replace it. The fix belongs in the same maintenance record — repairs, who did them and when, are part of what the template asks you to show. You may see other tolerance figures quoted around the internet; the ranges above are the ones in MPI's published guidance, so they're the ones to work to.

How often should you calibrate?

Your plan sets the rhythm, not this page. The template's "Maintaining equipment and facilities" card says to service your equipment regularly and, if necessary, calibrate according to your calibration schedule (SS&S template, Purple Card). MPI's calibration guidance suggests checking your thermometer every 6–12 months, or as per the manufacturer's instructions.

Some specialist processes are stricter — the template's sous vide card, for example, requires water baths to be calibrated at least monthly. And beyond the schedule, many kitchens sensibly re-check after anything that could knock accuracy out: a dropped probe, a battery change, a big thermal shock. That's good practice rather than an MPI requirement — the schedule in your plan is the commitment your verifier will look for.

What to write down when you calibrate

The shape of any NZ food-safety record is set by regulation 37 of the Food Regulations 2015: a record of an activity must state the date (and time if appropriate), describe the results, and name or otherwise identify who performed it — and be kept for at least 4 years (regulations 36 and 81). Applied to a calibration, that's a one-line entry:

That single line, dated and initialled, is what turns "we calibrate our thermometers" from a claim into a record your verifier can read — and it's the same who/when/result shape every other record in your plan follows, from daily fridge checks down.

MPI's thermometer calibration record blank

When MPI refreshed the Simply Safe & Suitable record blanks in February 2026, the update added a dedicated "Thermometer checks/calibration" template alongside the new opening-and-closing and daily-cleaning sheets — and for the first time the blanks come in Word and Excel as well as PDF, so you can adapt them to your kitchen (MPI: Forms and documents for Food Act plans and programmes).

Our record blanks guide keeps the current download links in one place, and the free printable temperature log pairs naturally with it — a calibrated thermometer is what makes every line of that log worth the paper.

Where an app earns its keep: remembering the schedule

The calibration itself takes five minutes twice a year. The hard part is the other 363 days — remembering it's due, and finding the entry when your verifier asks eighteen months later. Paper handles neither well; a 6–12-month task is exactly the kind that falls off a wall calendar.

In the KitchenSorted app, a calibration is a maintenance-log entry like any other: dated, timed and initialled automatically — the who/when/result that regulation 37 asks of a record — with room for the readings if you choose to keep them. The free diary covers the logging; calibration reminders on your plan's schedule, verification packs and 4 years of searchable history live in the paid plan — and your free-plan records are never deleted, they simply unlock when you upgrade.

Thermometer calibration FAQs

Is logging thermometer calibration results mandatory in NZ?

No. MPI's February 2026 Record keeping guidance marks thermometer checks/calibration results as optional to record. What is mandatory is the equipment-maintenance record — which includes calibrating your own thermometer, who did it and when. Keep the readings anyway if you can: they're effortless evidence.

Do I need to send my thermometer away for professional calibration?

The Simply Safe & Suitable template doesn't ask for that — the maintenance record MPI describes covers calibrating your own thermometer, and MPI's calibration guidance is a self-check you can do at the bench with ice slush and boiling water. Follow your thermometer manufacturer's instructions too; if yours specifies professional servicing, that becomes part of your maintenance schedule.

Does the fridge's built-in display count as a calibrated thermometer?

No — the template's "Keeping food cold" card is explicit that you cannot rely on the temperature shown on your fridge or chiller (SS&S template, Green Card). Your daily check is of the food, using a calibrated probe, infrared thermometer or automated system — here's the full fridge-temperature guide.

What accuracy should a food thermometer have?

MPI's published check ranges are the practical answer: reading ice slush, a healthy thermometer shows between −1°C and 1°C; in boiling water, between 99°C and 101°C (MPI thermometer calibration guidance). A thermometer outside those ranges needs adjusting or replacing before you trust it with a cooking or chilling decision.