The Food Safety AppThe probe calibration record behind every other temperature
Every cooking, cooling and chilling record in the pack is a number read off one thermometer. If that thermometer is two degrees out, so is the whole pack, and the question an officer asks about it is short: how do you know it reads true?
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This is the record the rest of the pack leans on. The temperature sheets most kitchens use have printed forms behind them, and SFBB publishes no form for the check that makes their numbers mean anything, so this is a plain page of ours.
The app is already asking you about it. Its own four-weekly review puts the question directly: have probes been calibrated in the last four weeks and the results recorded? This record is the evidence behind whatever you answered.
The question behind every other temperature
A kitchen can keep a flawless month of fridge readings on a probe nobody has ever checked, and an officer who notices will treat the whole month differently. It is not scepticism about the kitchen, it is that an unverified instrument produces unverified records.
Two readings in a jug of water settle it, and they take about two minutes.
The two readings
| Test | A probe reading true shows |
|---|---|
| Iced water | between -1 °C and 1 °C |
| Boiling water | between 99 °C and 101 °C |
Both are recorded, with the date and who did it, because a probe can be right at one end of its range and wrong at the other.
How often
The app treats a probe as due again thirty days after its last check, which lines up with the four-weekly review asking about it. A probe that has never been checked is due now.
If you have more than one thermometer, they are checked and recorded separately. A calibrated probe in a drawer does not vouch for the one in somebody’s apron.
When a probe fails
A failed check is not a problem for the record, it is the reason the record exists. What matters is what happened next, so the app asks you to say which:
- Replaced. The probe is retired and stops appearing as something to check, because a thermometer in the bin does not need calibrating every thirty days.
- Sent for calibration. It is out of the kitchen and coming back. The record keeps the gap rather than pretending there was not one.
- Still in use. Sometimes the honest answer, and the app records it as a decision somebody made rather than quietly dropping the failure.
Questions
Is there an SFBB form for probe calibration?
No. SC2, SC3, SC4 and the Prove It sheet all have one and this does not, so the app prints a plain A4 table of its own into the inspection pack.
How do I calibrate a probe without equipment?
The two tests above need a jug, ice and a kettle. Iced water should read about zero and boiling water about one hundred, and the app records what yours actually read rather than what it should have.
What if the probe is a few tenths out?
The app treats -1 °C to 1 °C and 99 °C to 101 °C as reading true. Outside that band it asks what you did about it, and the three answers it accepts are replaced, sent for calibration, or still in use.
Does the four-weekly review fill this in for me?
The other way round. The review asks whether probes have been calibrated and recorded in the last four weeks; this record is what makes a yes true.
Keep reading
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