In this guide 6 sections
Plan the flow in four links. Probe readings are logged at set intervals, thresholds raise an alarm, a named person acknowledges it, and a corrective action is recorded against the chamber and load. Keep all four in a single record, so the auditor reads one chamber’s full story without chasing the logger, the roster and the stock file separately.
List every chamber, probe and product class
Begin with an inventory. For each chamber or reefer, note the probe ID, its position, the last calibration date and product class, since frozen goods, chilled produce and pharma lots need different limits.
Decide what a reading means. Ask whether it is air temperature or a simulated product probe, and where the probe sits relative to the door and the evaporator. Readings near the door swing more.
Write the answers down before you choose any tool, because a data logger bought first will shape the plan around its own limits instead of around your chambers. Plan before you buy.
- Chamber or vehicle ID and product class
- Probe ID, location and calibration due date
- Reading interval, such as every five minutes
- Upper and lower limit per product class
- Defrost cycles that cause expected spikes
Set thresholds and delays that avoid noise
A single high reading during a door opening is not an excursion, so set a delay, such as ten minutes above the limit, before an alarm fires. Use short delays on frozen goods. Allow longer ones during scheduled defrost.
Two levels work best. A warning tells staff to check the door or the compressor, while a critical alarm means stock is at risk and the quality manager must be told at once.
False alarms teach people to ignore them. Silence follows, a real alarm gets missed, and so the threshold list needs a review after the first fortnight, with every nuisance alarm removed.
Decide who is told, how, and how fast
Name a responder per shift. Alerts should reach a backup and the first responder by phone call or message, not only by email, because night shifts need something that wakes a person up.
Every alarm needs an acknowledgement. An alarm that nobody accepts should escalate after a set time to the quality manager and then the operations head, and the record shows who saw it and when.
Keep a duty roster inside the system so alerts follow the person on shift, because a message sent to someone on leave helps nobody, so check the roster weekly.
- First responder and backup per shift
- Alert by call or message with chamber name
- Acknowledgement within a stated time
- Escalation steps if nobody responds
- Silence option only with a reason entered
Record the corrective action against the load
At closure the responder enters the cause, whether a door left open, a compressor trip, a power cut or a defrost fault, and lists every lot in the chamber. Each lot gets a recorded outcome.
Quality owns the call. Quality decides the disposition: hold, test, release, return to the supplier or destroy, with the decision, the name and the date sitting on the same record as the readings.
Link the record to the goods receipt and dispatch documents, so a customer who asks about a pallet receives the full temperature history for its stay in your chamber.
Test the flow before the audit does
Run a live drill. Warm a probe in a cup of water, or simulate a reading, and watch the chain of alarm, call, acknowledgement, escalation and entry of action, timing each step.
Print one chamber’s record for a month and read it as an auditor would, because gaps in readings, uncalibrated probes and open alarms stand out quickly on paper.
Fix what the drill exposes. Repeat it every quarter, and run it again after any change of probe, chamber layout or shift roster, since each change can break a link in the alert chain.
Excursion response record
One form per event. The header names the chamber, probe, product class, limit and the time the alarm fired, and the rows below capture acknowledgement time and name, probable cause and lots affected. A last block takes the quality decision, the corrective action, the sign-off and the date on which the probe that raised the alarm was last calibrated.
Open a blank worksheet to printQuestions owners ask
What is a temperature excursion in cold storage?
It is a period when stored goods sit outside their allowed temperature range, with limits that come from the product, the customer contract or the applicable regulation. The record shows duration and action.
How often should probes log temperature?
Many operators log every few minutes. The interval should be short enough to show a rise before stock is affected, so check your customer requirements and any regulatory guidance for your product type.
Who should get the alarm?
A named first responder on shift gets it, with a backup beside them and an escalation path up to the quality manager if nobody answers. Alerts should reach a phone.
Do I need software or will a data logger do?
A logger captures readings. A system adds alarm routing, acknowledgement and corrective action in one record, so when an auditor asks who responded and what happened to the stock, it answers faster.