LACO has been a trusted and accredited provider of calibrated helium leak standards since 1998. With over 26,000 CalMaster leak standards manufactured, we have the experience and technology to ensure your leak testing success. Our leak standards are NIST traceable and our labs holds A2LA accreditation to both ISO 17025:2017 and ANSI/NCSL Z540-1-1994 standards.

Our leak standards utilize proprietary micro-tube capillary technology and stand as the foremost leader in the industry for its unparalleled stability and reliability. These leak standards are available in both reservoir and open-style configurations. For leak rates in the 10-9 range and lower, select a permeation style helium leak standard with reservoir.


  • Stable and reliable leak standards
  • Standard and custom design options
  • Broadest range of leak rates (10-10 to 84 atm-cc/sec) and gases offered
  • Easily refillable reservoirs
  • Standard designs available in 3 weeks, expedited options available
  • High quality stainless steel welded construction
  • Lifetime product warranty
  • Responsive technical staff

Our helium leak standards are used in a variety of applications including calibrating helium mass spectrometer leak detectors and helium leak test systems. Open-style helium leak standards can be built into customer test parts. For calibrating helium sniffer probe leak detectors see our Sniffer Leak Standards. We also offer OEM replacement leak standards for many models of helium mass spectrometer leak detectors, including LACO's TITAN VERSA helium leak detector.