This is a ready-to-use OQ/PQ thermal mapping protocol for a reach-in stability chamber, refrigerator, or freezer. Replace every <<FILL: ...>> placeholder with your specifics. A worked filled specimen follows. Acceptance criteria must be approved before execution; never write them after seeing the data.
Approval page
| Role | Name | Signature | Date |
|---|---|---|---|
| Author (qualification engineer) | <<FILL>> | ||
| Reviewer (equipment owner) | <<FILL>> | ||
| Reviewer (metrology) | <<FILL>> | ||
| Approver (Quality Assurance) | <<FILL>> |
Pre-execution approval confirms the acceptance criteria in section 6 were defined before any data was collected.
| Field | Entry |
|---|---|
| Protocol number | <<FILL: e.g. PQ-CHM-014>> |
| Version | <<FILL: 1.0>> |
| Parent SOP | <<FILL: SOP-ID for thermal mapping program>> |
1. Objective
To demonstrate that <<FILL: UNIT NAME / ASSET ID>>, rated <<FILL: e.g. -20 degrees C +/- 5>>, holds its rated condition at every position in the usable volume, empty and under worst-case load, and recovers within limits after routine door access.
2. Scope
This protocol covers OQ empty-chamber distribution, PQ loaded distribution, and door-open recovery for the unit above. It does not cover IQ (installation), which is complete under <<FILL: IQ report reference>>, nor routine calibration of the unit’s control sensor, governed by <<FILL: calibration SOP-ID>>.
3. System description
| Field | Entry |
|---|---|
| Unit type | <<FILL: stability chamber / refrigerator / freezer>> |
| Asset ID | <<FILL>> |
| Rated condition | <<FILL: temperature +/- tolerance, and RH if applicable>> |
| Usable volume | <<FILL: dimensions / shelf range, load lines marked>> |
| Control sensor location | <<FILL>> |
| Defrost | <<FILL: type and frequency, or None>> |
| Monitoring point (BMS/chart) | <<FILL>> |
4. Prerequisites
- IQ complete and approved; unit installed, powered, and at steady state.
- Data loggers calibrated pre-study (certificates attached), traceable to a national standard, calibrated at points bracketing the setpoint.
- Measurement uncertainty confirmed to consume no more than about a quarter to a third of the band.
- Sensor placement diagram approved (attachment A).
- Worst-case load defined and available for the PQ (attachment B).
5. Roles
| Role | Responsibility |
|---|---|
| Executor | Places loggers, runs the study, downloads data, records results. |
| Reviewer | Independent review of raw data and calculations. |
| QA | Approves the protocol, criteria, and report; dispositions deviations. |
6. Acceptance criteria
| # | Criterion |
|---|---|
| AC-1 | All mapped loggers hold the rated band at steady state (excluding defined defrost transients). |
| AC-2 | Instantaneous spatial spread across loggers is within <<FILL: e.g. the band>>, outside defrost. |
| AC-3 | The control sensor agrees with the co-located logger within <<FILL: e.g. 1 to 2 degrees C>>. |
| AC-4 | During any defrost, warming stays within band or returns within <<FILL: minutes>>. |
| AC-5 | After a <<FILL: e.g. 90 second>> door-open, no logger exceeds the excursion limit beyond the defined recovery time, and the unit returns to band within <<FILL: minutes>>. |
| AC-6 | All loggers pass post-study calibration; any out-of-tolerance logger invalidates its data and the affected result is re-run. |
7. Test cases
| ID | Step | Expected result | Actual | Pass/Fail | Tester | Date |
|---|---|---|---|---|---|---|
| TC-1 | Verify each logger ID against the placement diagram and confirm clocks are synchronized | All IDs match attachment A; clocks synced within <<FILL: seconds>> | <<FILL>> | |||
| TC-2 (OQ) | Run empty-chamber distribution for <<FILL: >= 24 h, including a defrost>>; record min/max/mean per logger | All loggers meet AC-1, AC-2; hot and cold spots identified | <<FILL>> | |||
| TC-3 (OQ) | Compare control sensor to co-located logger across the study | Agreement within AC-3 | <<FILL>> | |||
| TC-4 (PQ) | Load worst-case configuration (attachment B); run distribution for <<FILL: >= 24 h>> | All loggers meet AC-1, AC-2 under load; loaded hot/cold spots identified | <<FILL>> | |||
| TC-5 | Capture at least one full defrost cycle within the study window | Defrost transient meets AC-4 | <<FILL>> | |||
| TC-6 | Open the door for <<FILL: duration>>, then close; record warming and recovery | Meets AC-5 | <<FILL>> | |||
| TC-7 | Post-study calibration verification of all loggers | All pass; meets AC-6 | <<FILL>> |
8. Deviation handling
Any result outside acceptance is recorded as a deviation under <<FILL: deviation SOP-ID>>, assessed for impact, and dispositioned before the protocol is closed. A failing logger invalidates only its own data; the affected position is re-run. Corrective changes to the unit (setpoint recentering, airflow fix) require a fresh confirming map.
9. Summary and conclusion
| Field | Entry |
|---|---|
| Hot spot (position) | <<FILL>> |
| Cold spot (position) | <<FILL>> |
| Worst-case load hot/cold spot | <<FILL>> |
| Recommended routine monitoring location | <<FILL>> |
| Recommended alarm setpoints | <<FILL>> |
| Deviations and disposition | <<FILL: none, or list>> |
| Overall result | Pass / Fail |
10. Attachments
- Attachment A: sensor placement diagram and location rationale.
- Attachment B: worst-case load photographs and description.
- Attachment C: pre- and post-study calibration certificates.
- Attachment D: raw logger data files.
11. References
21 CFR 211.63, 211.68 (equipment suitability and controls). ICH Q1A(R2), Stability Testing (for stability-chamber conditions). WHO Technical Report Series guidance on temperature mapping of storage areas. USP General Chapter 1079, Good Storage and Distribution Practices (MKT).
Confirm the current version of each reference before issue.
Filled specimen
The following shows the protocol executed for an example upright freezer rated -20 degrees C +/- 5, 48 hour loaded study. The specifics are illustrative.
Test cases (excerpt)
| ID | Step | Expected | Actual | Pass/Fail |
|---|---|---|---|---|
| TC-4 (PQ) | Loaded distribution, worst-case full load, 48 h | All loggers within -25 to -15 outside defrost | Door logger T11 max -15.4; coil logger T12 min -24.1; all within band outside defrost | Pass |
| TC-5 | Capture defrost | Transient within band or recovers within 20 min | Spread reached 6.9 C during defrost, recovered in 14 min | Pass |
| TC-6 | 90 s door-open | Recovers to band within 15 min | Warmest logger reached -14.9 C briefly, recovered in 8 min | Pass with deviation |
| TC-7 | Post-study calibration | All loggers pass | All 12 loggers passed | Pass |
Summary: hot spot at the door (T11), cold spot at the coil (T12). The 90 second door-open transient reached -14.9 degrees C, a brief excursion of the -15 band edge, recorded as DEV-2026-0210 and dispositioned as acceptable under a defined maximum door-open time SOP limit, with the top-door storage line lowered. Routine monitoring probe recommended at the door zone (T11) as the first-to-excurse position; alarm setpoints set from the mapped envelope. Overall result: Pass.
In this example the door-open transient was not papered over; it was raised as a deviation, assessed, and closed with a real operational control (a door-open time limit and a lowered load line). That is the difference between a study that qualifies a unit and one that hides its worst behavior.
Common inspection findings this protocol prevents
- Acceptance criteria not pre-approved, or conveniently matching the observed spread.
- No loaded study, so the qualified state does not represent real use.
- Defrost never captured, then the unit excurses on defrost in production.
- A brief door-open excursion ignored rather than dispositioned.
- A routine probe left at the geometric center while the door is the true worst case.
How to adapt this protocol
- Set the protocol number, unit, and rated condition; fill the acceptance-criteria thresholds in section 6 for your band and recovery limits.
- For a stability chamber, add relative-humidity mapping loggers and RH acceptance criteria.
- Attach the approved sensor placement diagram (use the companion sensor-placement rationale form).
- Confirm every reference in section 11 against the current published version before execution.