Precision Leak Testing for Medical Fluid Pathways and Sealed Devices

Medical device airtightness testing operates at the intersection of regulatory compliance and physical performance limits. Fluid pathway tubing, surgical tools, and pharmaceutical packaging require leak detection at levels that conventional direct pressure testers cannot reliably achieve. Differential pressure methods eliminate environmental noise — delivering repeatable sub-0.01 kPa resolution at production speed.

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Case: Medical Fluid Pathway Tubing — Sub-SCCM Detection

Instrument: LD Series Differential Pressure Airtightness Tester
Connector: LT-D01 Inner-Expansion Quick Connector (Φ9.5–24.4 mm)

Test Parameter	Value
Test Pressure Range	95–500 kPa
Leak Threshold	3 SCCM / 0.2 kPa·min⁻¹
Detection Method	Differential pressure bridge
Sensitivity Advantage	10× vs. direct pressure at same test pressure

Challenge

Medical-grade fluid tubing for infusion and respiratory devices must meet sterile-barrier integrity standards where acceptable leak rates are measured in single-digit SCCM. Direct pressure testing at these specification limits generates an unacceptable rate of false rejects due to temperature and ambient pressure variation — particularly in air-conditioned clean room environments with active HVAC cycling.

Solution

The LD Series differential pressure bridge compares the test piece against a sealed reference volume in real time. Temperature and barometric changes affect both sides equally and cancel as common-mode noise. The LT-D01 inner-expansion connector seals medical soft tubing from the inside bore with no axial compression force, protecting fragile tube-wall geometry at the test point.

Result

• Reliable detection at < 0.01 kPa differential — suitable for sub-SCCM specifications
• Near-zero false-reject contribution from environmental fluctuation
• Non-destructive fixturing preserves soft tube wall integrity

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Case: Pharmaceutical Bottle Airtightness — LG Auto-Regulating

Instrument: LG Series Auto-Regulating Airtightness Tester
Fixture: Pneumatic clamshell fixture with custom sealing ring

Challenge

Pharmaceutical liquid vials require consistent airtightness validation at production throughput. Multiple bottle variants with different specifications are tested on the same line. Manual pressure adjustment between variants introduces operator error and increases changeover time.

Solution

The LG stores a pressure program for each bottle variant. The operator selects the product code from the touchscreen; the instrument sets the correct test pressure electronically without any manual knob adjustment. The pneumatic clamshell fixture closes and seals automatically.

Result

• Changeover between bottle variants: < 10 seconds (program recall only)
• Consistent sealing pressure across full production batch
• Operator-error contribution to false-reject rate eliminated for pressure setting

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Case: Medical Tubing Flow Validation — LF Flow Tester

Instrument: LF Series Gas Flow Tester
Application: Peristaltic pump and infusion tubing flow channel validation

Challenge

Infusion tubing must meet a defined flow rate specification at operating pressure — not just seal integrity. A tube that passes a pressure decay test may still have an undersized or oversized internal channel. Pressure testing alone cannot detect this class of defect.

Solution

The LF Series measures actual volumetric flow through the tubing at the specified supply pressure. Parts with correct internal geometry flow within the acceptance band. Parts with blocked, undersized, or oversized channels fall outside the band and are flagged NG.

Result

• Flow-based validation catches channel geometry defects invisible to pressure decay testing
• Test pressure configurable 0–1200 kPa to match operating conditions

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Recommended Configuration — Medical Applications

Application	Instrument	Connector
Fluid pathway tubing (micro-leak)	LD Series	LT-D01 (inner expansion, soft tube)
Surgical instrument sealed chamber	LD Series	LT-N01 (hand-screw internal thread)
Pharmaceutical bottle (multi-variant)	LG Auto-Regulating	Custom clamshell fixture
Flow channel validation	LF Series	Figurtech quick-seal per port size