Mass Flow Leak Test process graph showing the programmed test stages and pass/fail response

Zaxis Z8 air leak tester showing a production test screen

Leak Test Method

Mass Flow Leak Testing

A mass flow leak test measures the air flow through a connected component and compares the result with programmed minimum and maximum flow values.

Mass flow testing checks whether the expected amount of air passes through a component. The product connects to the test port, regulated air pressurizes it, and the system measures flow during the test phase.

A pressure sensor checks the test pressure against programmed tolerances while a mass-flow sensor measures flow. The tester compares the result with predefined minimum and maximum values and displays pass or fail.

Mass flow testing is used for catheters, IV sets, check valves, tubing, needleless injections, infusion sets and metering devices. It is non-destructive and well suited to production applications that need a repeatable flow-rate check.

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What is a mass flow leak test?

Mass flow testing measures flow through an object rather than pressure decay in a sealed object. The component connects to the test port and receives regulated air; during the test, the mass-flow sensor measures the air moving through it.

Acceptable results are defined by minimum and maximum flow values programmed for the part. A component within those values passes, confirming the expected flow rate; a component outside them fails.

Thermal mass flow measures gas flow by heating a sensor and calculating the energy needed to maintain a constant temperature. Laminar mass flow uses laminar-flow principles for precise liquid-flow measurement.

How a mass flow test runs

FILL

Attach the component to the test port and fill it with regulated air to the programmed test pressure.

STABILIZE

Allow the test pressure to reach the programmed tolerance before evaluating flow.

TEST

Measure flow with the mass-flow sensor and compare it with the programmed minimum and maximum values.

VENT

Complete the cycle and release the test pressure before the next part.

A component whose measured flow is within the programmed minimum and maximum values passes; a reading outside those values fails.

When mass flow is the right method — and when it is not

Mass flow is a fit when

✓A flow-through component with an expected flow range
✓A non-destructive production test
✓Catheters, IV sets, check valves, tubing and infusion sets
✓A need to compare measured flow with minimum and maximum values

Choose another method when

→A sealed part with no expected flow path — Use pressure decay testing.
→A need to determine whether a passage is blocked — Use occlusion testing.
→A need to locate the physical leak site — Use sniffing leak testing.

Sensitivity, cycle time and part volume

The test combines pressure control and flow measurement. Regulated air fills the component while the pressure sensor checks the programmed test-pressure tolerance and the mass-flow sensor measures flow.

Programmed minimum and maximum values define the accepted flow band. The tester compares the measured flow with those values and displays a pass or fail result.

The Isaac HD, iKit and Zaxis 7i all run mass flow tests. Their fixture connection and programmed sequence support repeated production checks.

Because the same connection, pressure tolerance and flow limits can be used for each component, mass flow testing can support automated production. The non-destructive result provides a direct quality decision without damaging the part.

Mass flow test schematic showing a tester measuring flow through a connected component

Which Zaxis testers run mass flow

Mass flow needs a tester with a mass-flow sensor in addition to the pressure sensor. These Zaxis testers run the mass-flow sequence.

Applications for mass flow testing

Catheters

Mass flow verifies the expected air path through catheter components.

IV sets and infusion sets

Flow-rate limits support checks of fluid-path components.

Check valves

Mass flow testing evaluates whether a check valve meets its expected flow range.

Tubing and needleless injections

Connected tubing and needleless injection components can be tested against programmed flow values.

Mass flow vs other leak test methods

Highlighted row is this method. ✓ yes · × no
Method	Non-destructive	Needs an access port	Locates the leak	Typical use
Pressure decay	✓	✓	×	Sealed parts with a port
Vacuum decay	✓	✓	×	Parts and packaging
Mass flow	✓	✓	×	Flow-rate limits
Occlusion	✓	✓	×	Blocked passages
Burst	×	✓	×	Failure pressure
Pressure cracking	✓	✓	×	Valve opening pressure
Chamber	✓	×	×	Sealed parts, no port
Sniffing	✓	✓	✓	Finding the leak site
Hard vacuum	✓	✓	×	Hermetic, safety-critical parts
Accumulation	✓	✓	×	Large parts, total leak rate
Bombing	✓	×	×	Sealed parts, no fill port
Differential pressure	✓	✓	×	Large volumes, low leak rates
Trace gas	✓	✓	✓	Very small leaks, quantified

Industries We Serve

Medical ManufacturingPrecision leak testing for critical medical components.

Automotive SystemsAir leak testing in manufacturing automotive components.

Electronics & ComponentProtecting quality in compact electronics and components.

Mass flow leak test FAQ

What is a mass flow leak test?

It measures air flow through a connected component and compares the reading with programmed minimum and maximum flow values.

What does a mass-flow sensor measure?

It measures flow during the test phase while the pressure sensor checks programmed test pressure.

How is a mass flow result judged?

A reading within the predefined minimum and maximum flow values passes; a reading outside them fails.

What components use mass flow testing?

Applications include catheters, IV sets, check valves, tubing, needleless injections, infusion sets and metering devices.

Is mass flow testing destructive?

No. It is a non-destructive test for flow-through components.

How is mass flow different from pressure decay?

Mass flow evaluates the amount of air moving through a component; pressure decay evaluates pressure change in a sealed part.

What is thermal mass flow?

Thermal mass flow measures gas flow by heating a sensor and calculating the energy needed to maintain a constant temperature.

Related leak test methods

→Pressure Decay →Vacuum Decay →Mass Flow →Occlusion →Differential Pressure →Chamber →Sniffing

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For HVAC and refrigeration components, see HVAC & Refrigeration Leak Testing for large-volume and refrigerant-circuit production test planning.