Helium Mass Spectrometry for Micro Leak Detection in Battery Envelopes
Inline helium mass spectrometry detects sub-micron battery envelope leaks down to 10-8 mbar l/s, preventing moisture-induced HF corrosion and solvent loss.
Ion Source Contamination
Meaning
Surface deposition processes accumulate unwanted chemical compounds on the ionization electrodes of analytical instruments, degrading signal quality. In vacuum leak detection systems for batteries, ion source contamination occurs when evaporated electrolyte solvents enter the mass spectrometer. The volatile organic molecules are cracked by the hot filament, forming carbonaceous or insulating layers on the electrostatic lenses.
This accumulation alters the trajectories of ionized tracer gas molecules, causing a loss in mass resolution and sensitivity during the cell inspection process.
Degradation Source
High-vacuum systems pull volatile compounds from imperfectly sealed cells or contaminated test fixtures. These vapors condense on the cooler surfaces of the analyzer, distorting the electric fields used to focus the ions. The resulting loss of signal resolution reduces the accuracy of the leak measurements.
System Maintenance
Preventing this buildup involves utilizing liquid nitrogen cold traps or heated analyzers that discourage solvent condensation. Regular cleaning requires abrasive polishing of the lenses and replacing the contaminated filament assemblies. This maintenance schedule directly impacts the operational availability of high-throughput test lines.
Production Outcome
A drift in calibration due to deposited residues leads to false acceptances of leaking cells. To prevent this risk, automated systems run periodic reference tests using calibrated leak standards. This verification ensures the integrity of the quality control process.