1. An Introduction To Helium Leak Detection Technology Darrell R. Morrow, PhD Leak Detection Associates, Inc. Blackwood, New Jersey

2. Why Helium? F Low Background (5-20 PPM) F Inert F Safe F Light F Low Cost ? He N O F Ne Cl Ar Kr Xe H

3. Why A Helium Leak Detector? SIMS 180TD+ F High Sensitivity F Wide Range F Reliable F Quantitative F Dynamic Testing F NIST Traceable

4. Analyzer Cell 180 o Deflection +200V VAR. FILAMENT GROUND TRIODE PLATE HEAVY IONS HELIUM IONS LIGHT IONS REPELLER HIGH POWER SUPPLY LOG AMPS - + TARGET RESISTANCE HIGH VACUUM GAUGE GROUND MAGNET

5. Helium Test Methods “Hard” Vacuum Helium Pre-Filled Samples SIMS 180TD+ 1E-2 mbar

6. Helium Leak Methods Sniffing Test He 100% He SIMS 180TD+ ALCATEL

7. Helium Leak Testing: Vacuum Mode F The “hard” vacuum test procedure measures the package’s cumulative leak rate arising from all sources within the sample. F This method enables the barrier performance of seals to be quantified.

8. Helium Leak Testing: Sniffer Mode F Individual packages containing helium can be checked for leaks using a pencil-sized vacuum collector (sniffer) attached to a helium leak detector. F The rate of gas sampling (flow rate) is set at 1cc/second; enabling a (ambient pressure) leak rate to be measured in ppm, or in cc/second. F The sniffer mode test procedure is “site- specific” in that the probe collects helium escaping within ~ 1/8” of the leak site.

9. Virtual Leaks and Outgassing Virtual leaks are small trapped volumes of gas at atmospheric pressure within the vacuum envelope which communicates with the vacuum system by means of minute crevices, cracks, grooves, etc. Outgassing is the desorption of atmospheric gases and contamination from the surface area within the vacuum system.

10. Fine Leak Rate Reality Theoretical hole diameter calculation in molecular flow regime D = M L 1 6Q 0.33 2 RT P 1 -P 2 CONDITIONS 1E-6 atm cc/sec. He leak rate 0.6 cm. wall thickness 20 C ambient temperature Inboard He spray test D = 4 (.6)(1)(6E-6) 0.33 2 (8.32E7)(293) Size (microns).0001.001.01.1 1 10 100 1,000 10,000 Pollen Microbes Lint Tobacco smoke Household dust Industrial dust Acid fumes Gas molecules Finger prints Alcohol residue D =.0009 cm. = 0.9 microns 1 meter = 1,000,000 microns

11. Pharmaceutical/Device Package Test Methods F Leak Test Methods Principles u The most common concept behind the « rapid » detection of leaks in various packaging forms is the monitoring of changes in specific physical parameters such as fluid (gas/vapor/liquid) transport from one side of a « sealed » package to the other, such as bubble formation or pressure changes.

12. Pharmaceutical/Device Package Test Methods F Existing Test Methods u Bubble Generation Test - Vacuum (ASTM D 3078-94) u Bubble Generation Test - Internal Pressurization (ASTM F 515-95) u Pressure Decay Test u Dye Penetration Test u Tracer Gas Leak Detection Test/s - Helium, Oxygen, Argon, CO 2