Guide · GxP
GxP temperature monitoring: what a system needs for freezers and cold rooms.
A thermometer tells you the temperature. A GxP monitoring system tells you, and proves later, that every unit stayed in range and that every alarm was acted on.
A GxP temperature monitoring system records the temperature of freezers, refrigerators, cold rooms and storage areas continuously, alarms when a limit is crossed, and keeps records that a regulated organisation can show to an inspector as evidence.
The parts of a GxP monitoring system
| Part | What it must do |
|---|---|
| Sensors | Read each unit and, where needed, product probes and door contacts |
| Alarm engine | High, low, rate of change, communication loss and sensor failure |
| Escalation | Reach someone who acts, at any hour, until acknowledged |
| Excursion record | Duration, peak, cause and disposition for every event |
| Calibration | Due dates tracked so no sensor runs out of calibration |
| Audit trail | Readings, alarms and actions kept, time-stamped and unalterable |
| Validation | Installation, operational and performance qualification |
Checklist before you buy
- Can it use the sensors and building-management equipment you already have?
- Does an alarm keep escalating until a named person acknowledges it?
- Does every acknowledgement require a reason?
- Is the audit trail append-only, and how long is it retained?
- Are validation documents part of delivery?
- Can QA pull six months of evidence in minutes?
For excursions on the road rather than in storage, read temperature excursion response in transit.
How ColdWatch does it
ColdWatch monitors freezers from −80 °C to cold rooms at 2–8 °C, plus product probes and door contacts, on the sensors you already have, over BACnet/IP or Modbus TCP. It raises five alarm types (high, low, rate of change, comms gap and sensor failure) and escalates by screen, email, SMS and push until someone acknowledges with a mandatory comment. AI projects drift forward to say which unit is likely to breach next and roughly when. Excursions go into a register with duration, peak, shift and severity; calibration due dates are tracked with reminders at 30, 15 and 7 days; and every reading, alarm and action is kept in an append-only ALCOA+ audit trail for five years, with IQ/OQ/PQ documents delivered as part of go-live.
Questions
What is a GxP temperature monitoring system?
A system that continuously records storage temperatures, alarms and escalates on limit breaches, and keeps validated, time-stamped records that can be shown to an inspector.
Do I need new sensors for continuous monitoring?
Not always. Systems that speak BACnet/IP or Modbus TCP can often read the sensors and building-management equipment already installed.
What does validation include?
Typically installation, operational and performance qualification (IQ/OQ/PQ) against your requirement specification.
See it on your own data. ColdWatch — Every freezer, every minute. Book a 30-minute working session with an engineer.