Home > How It Works – Micro-Flow & Mass Extraction

How It Works – Micro-Flow & Mass Extraction

The leak flow measurement is based on the mass conservation law, where the IGLS measures, unlike other traditional methods, the flow rate of make up air added to the unit under test. The incoming flow rate at steady state condition is equal to the amount of mass leaking out.

Pressure Testing

ATC measure air flow from leaks

Pressure testing diagram

Method of Operation

Pressure method diagram

What it Does

Basically measures the “make up flow” to hold constant pressure and this is the leak flow rate.

The Intelligent Gas Leak Sensor (IGLS) operates in the viscous and slip flow regimes

  • Sensors with full scale as low as 0.025 cc/mm (~4×10-4 cc/sec.)
  • Measures volume flow, P, T
  • Momentum loss causes electrical signal, proportional to volume flow (cc/min)

Why It’s Better

  • Faster leak test compared to pressure decay for same capability.
  • Stable measurement, environmental (temperature) insensitive compared to pressure decay or mass flow.
  • Sensitivity – Replaces helium with air test.
  • No vacuum.
  • Simpler to operate.
  • Less equipment & operation expense than helium testing.
  • Direct measurement – does not require frequent calibration.
  • Measurement is not part volume sensitive.
  • Multiple parts tested with one instrument & sort option.

Mass Extraction

ATC measure air flow from leaks

Mass extraction diagram

Method of Operation

Mass extraction method diagram

What it Does

ATC’s patented Micro-Flow Technology is a revolutionary alternative to other leak detection methods.  It measures the amount of air extracted from a sealed part/closure, which is proportional to its defect size. ATC’s IGLS micro-flow sensor is more sensitive due to gas expansion at vacuum conditions. ATC, Inc. offers two operational regimes:

  • IGLS sensor operates in slip/viscous flow and vacuum from 2 psia to barometric condition (detection of defects from 1 micron).
  • IMFS sensor, operates in transitional and molecular flow regimes (air flow from 6×10-7 sccs) detects from 0.1 micron.

ATC, Inc. instruments can measure air extracted from your part in one of the following configurations:

  • Sealed part, inside a vacuum chamber.
  • Pressurized part, inside a vacuum chamber.
  • Vacuum pulled from inside the part, part not in a chamber.
  • Vacuum pulled from inside the part, part exposed to pressure on outside.

Why It’s Better

  • Nondestructive.
  • Shorter cycle time.
  • Direct measurement of leak flow.
  • Operates in helium mass spectrometry ranges.
  • No tracer gases.
  • Insignificant temperature sensitivity.
  • Does not require hard vacuum for most applications.
  • Reduces your maintenance and operation cost.