# Viamed Ltd
## Follow-Up Leakage Investigation - Stock Reference 0110051, Oxygen Sensor T-1

**Document status:** Follow-up report  
**Review date:** 29 July 2026  
**Prepared for:** Viamed Ltd  
**Supplier:** Teledyne Analytical Instruments  
**Stock reference:** 0110051  
**Product:** Oxygen Sensor T-1  
**Manufacturer date codes reviewed:** B6 and E6  
**Linked investigation:** Supplier Batch Quality Investigation - Stock Reference 0110051, Date Code B6

---

## 1. Purpose of Follow-Up

The original supplier batch quality investigation identified fifteen leaking sensors carrying manufacturer date code B6. These failures were detected during Viamed's incoming QA and were contained before supply.

As an immediate containment action, all remaining date-code B6 sensors held by Viamed that had previously passed incoming QA were subjected to repeat leakage testing. The two E6 sensors received within purchase order PVM4943 were also checked because they had been physically received within the same mixed receipt.

This follow-up report records the repeat-test results, updates the known failure rates and reassesses the scope of the supplier-quality concern.

---

## 2. Repeat Leakage Test Findings

Five additional B6 sensors were found to leak during repeat testing.

| Serial number | Date code | Original receipt | Result |
|---:|---|---|---|
| 338707 | B6 | PVM4583 - 11 February 2026 | Leaked |
| 338714 | B6 | PVM4583 - 11 February 2026 | Leaked |
| 338718 | B6 | PVM4583 - 11 February 2026 | Leaked |
| 338744 | B6 | PVM4583 - 11 February 2026 | Leaked |
| 338797 | B6 | PVM4943 - 6 May 2026 | Leaked |

These five units had passed the original incoming QA inspection but failed when rechecked.

A further failure was identified in one of the two E6 sensors:

| Serial number | Date code | Original receipt | Result |
|---:|---|---|---|
| 360551 | E6 | PVM4943 - 6 May 2026 | Leaked |

The second E6 sensor, serial number **360550**, passed the repeat leakage test.

---

## 3. Updated B6 Position

The original investigation recorded fifteen B6 failures from 118 B6 sensors received. The repeat test identified five additional B6 failures.

| B6 status | Quantity |
|---|---:|
| B6 sensors received | 118 |
| Original incoming QA failures | 15 |
| Additional repeat-test failures | 5 |
| **Total known B6 failures** | **20** |
| **Revised known B6 failure rate** | **16.9%** |
| B6 sensors previously supplied | 61 |
| B6 sensors remaining held and passing repeat test | 37 |

### B6 failure rate by receipt

| Purchase order | B6 received | Original failures | Repeat-test failures | Total known failures | Revised failure rate |
|---|---:|---:|---:|---:|---:|
| PVM4583 | 100 | 11 | 4 | 15 | 15.0% |
| PVM4943 | 18 | 4 | 1 | 5 | 27.8% |
| **Total** | **118** | **15** | **5** | **20** | **16.9%** |

---

## 4. E6 Position

Viamed records show that only two sensors carrying date code E6 have ever been received. Both were included in purchase receipt PVM4943.

| E6 status | Quantity |
|---|---:|
| E6 sensors received | 2 |
| E6 sensors failed on repeat test | 1 |
| E6 sensors passing repeat test | 1 |
| Observed failure proportion | 50% |

The observed E6 failure proportion must be interpreted cautiously because it is based on only two units. Nevertheless, the finding is important because it shows that the leakage concern is not confined exclusively to date code B6.

---

## 5. Significance of the Follow-Up Findings

The repeat-test results materially change the original assessment.

The initial investigation showed that Viamed's incoming QA successfully detected fifteen leaking B6 sensors before they were supplied. The follow-up now shows that five additional B6 sensors which originally passed incoming QA subsequently leaked when rechecked.

This indicates that:

- leakage may develop after the original incoming inspection;
- the defect may be latent or intermittent;
- a single satisfactory leakage test may not provide assurance that an affected sensor will remain leak-free;
- the scope may extend beyond date code B6, because one E6 sensor also failed;
- the concern cannot be attributed solely to the original fifteen units already placed in supplier-return boxes.

The test-equipment evidence considered in the original investigation remains valid. The DVM used for QA was within Viamed's defined verification period and had passed verification against calibrated reference equipment. No new evidence has been identified suggesting that the repeat failures were caused by the measuring equipment.

---

## 6. Customer Exposure

Sixty-one B6 sensors had already passed incoming QA and were supplied before the repeat testing was undertaken. The customer traceability records identify the affected customer accounts by internal company ID:

- CID13568;
- CID4760;
- CID5051.

No customer returns or recorded field failures have been identified against those supplied B6 sensors in the available IntraStats data.

However, because five retained units passed initially and later leaked, the original incoming pass result can no longer be treated as complete assurance that every supplied B6 unit will remain leak-free. A documented risk-based decision is therefore required regarding continued monitoring, supplier advice and whether any customer communication or other field action is necessary.

---

## 7. Containment and Follow-Up Actions

### Internal containment

- Segregate the five newly failed B6 sensors.
- Segregate failed E6 serial number 360551.
- Add the six new failures to the linked supplier nonconformance and supplier-return records.
- Retain the completed warehouse repeat-test sheet as objective evidence.
- Keep the 37 remaining passing B6 sensors under controlled hold pending management disposition.
- Keep E6 serial number 360550 under controlled hold pending supplier and management review.
- Record the repeat-test date, tester and equipment used against the affected serial numbers.

### Supplier escalation

Teledyne should be informed that:

- the known B6 failure total has increased from fifteen to twenty;
- five additional B6 sensors failed after previously passing incoming QA;
- the revised known B6 failure rate is 16.9%;
- the May B6 receipt now has a known failure rate of 27.8%;
- one of the two E6 sensors received has also leaked;
- the concern may involve latent leakage and may not be limited to date code B6.

Teledyne should be requested to provide:

- a formal root-cause investigation;
- confirmation of the affected manufacturing and date-code range;
- an explanation of how sensors can pass initial testing and subsequently leak;
- advice on the reliability and disposition of units that currently pass repeat testing;
- advice concerning the 61 B6 sensors already supplied;
- corrective and preventive action;
- replacement or credit for all confirmed failed units.

### Customer and field review

- Continue active monitoring of complaints, returns and service information for the 61 supplied B6 sensors.
- Retain the barcode, serial, invoice and CID traceability data with the issue.
- Complete and document a risk assessment before deciding whether customer notification or other field action is required.
- Escalate promptly if any customer leakage, performance complaint or related incident is reported.

---

## 8. Updated Assessment

The follow-up evidence supports the following assessment:

1. **The B6 failure level is higher than initially established.**  
   Twenty of 118 B6 sensors are now known to have leaked, representing 16.9%.

2. **Some failures are latent or were not detected during the first test.**  
   Five B6 units passed incoming QA but leaked during repeat testing.

3. **The issue may not be restricted to B6.**  
   One of the two E6 sensors received also leaked.

4. **Viamed's decision to recheck retained stock was effective.**  
   The repeat testing prevented six further leaking units from being released.

5. **The customer-exposure assessment requires review.**  
   Sixty-one B6 sensors were supplied after passing the same incoming QA process, although no customer failures are currently recorded.

6. **Supplier root-cause and scope confirmation are now essential.**  
   The available internal evidence cannot establish whether the cause is material, sealing, manufacturing process, ageing or another supplier-controlled factor.

---

## 9. Conclusion

Repeat leakage testing of the retained stock identified five further leaking B6 sensors and one leaking E6 sensor.

The known B6 failure total has therefore increased from fifteen to twenty out of 118 sensors, giving a revised known failure rate of 16.9%. The later PVM4943 B6 receipt has five known failures from eighteen B6 sensors, representing 27.8%.

The most significant finding is that five B6 sensors which passed the original incoming QA subsequently leaked during repeat testing. This demonstrates that the concern is not limited to units that fail immediately on receipt and raises the possibility of latent or developing leakage.

The E6 finding broadens the potential scope. Only two E6 sensors were received and one has failed. This is too small a population for statistical conclusions, but it prevents the investigation from being treated as exclusively a B6 date-code issue.

Viamed's containment action was effective and stopped six additional leaking sensors from being released. The issue should remain open as a formal supplier nonconformance. The retained B6 and E6 stock should remain controlled until a documented disposition decision is made, and Teledyne should be required to address the expanded failure data, the possibility of latent leakage, the affected manufacturing scope and the position of units already supplied.

---

## 10. Updated Classification

**Issue type:** Supplier nonconformance / incoming and latent product quality failure  
**Current impact:** Additional internal failures identified and contained  
**Known B6 failures:** 20 of 118 (16.9%)  
**Known E6 failures:** 1 of 2  
**Customer complaints identified:** None in available records  
**Known customer field failures:** None in available records  
**Customer exposure:** 61 B6 sensors supplied to CID13568, CID4760 and CID5051  
**Supplier escalation required:** Yes - expanded investigation  
**Internal stock disposition required:** Yes  
**Customer/field risk assessment required:** Yes  
**Issue status:** Remain open pending supplier response, risk assessment and stock disposition