An Introduction to CTS Leak Standards

June 21, 2022 | By Michelle Woelfel, Customer Service Lead

Leak masters are a certified part calibrated to a specific leak rate and pressure. They can be used to calibrate a leak test instrument in test lines and manifolds, or in a master part. A standard CTS leak orifice is made up of a crimped stainless-steel rod, inside a holder of your choice, that is certified to flow at a specific controlled leak rate when pressurized.  

How to Specify a Leak Master
We understand everyone’s testing needs are different and want to ensure you have the right leak test for your application. CTS leak standards are custom-made to order, not pre-made and sitting on a shelf. We offer a standard manufacturing tolerance at +/-1% or 0.1 scc/m, whichever is greater. Each leak standard comes labeled with a serial number, and individual certificate of calibration.

The default calibration gas is nitrogen, but we do offer many other nonflammable gas options if requested. We also offer a variety of holders with different inlets and outlets to fit your application, whether you are using the leak in a CTS instrument or in another application.

If leak testing is new to you, we have resources available such as our online leak rate calculator, and representatives with leak testing expertise who can assist with your application. Once you are ready for a quote contact us with the following information:

  • Leak rate (with units)
  • Pressure (with units)
  • Holder style, or confirmation of your CTS leak test instrument
  • Calibration gas

If you are ordering a duplicate leak standard to one you already have, you can simply provide the serial number.

You will receive a formal quote within 24 hours.

See Our Full Catalog of Air Flow and Tracer Gas Leak Standards >>


Re-certification of Leak Standards is Key to Preventing Downtime
To ensure your leak standard is reading at the appropriate specification, we recommend annual recertification. Over time the orifice may become susceptible to dirt and debris from dirty shop air, dusty work environments, moisture, or other contaminants. If a leak standard is reading outside of your allotted spec, you are running the risk of inaccurate testing, which could result in recalls or failing good parts.

When testing a standard leak master, the recalibration tolerance is +/-5% from last calibration, and 20% from original spec. CTS offers recertification in our onsite A2LA ISO 17025 accredited lab. Our turnaround time is quick with an average of 6 business days or less and includes automatic replacement at no additional charge if a CTS leak standard is found out of tolerance. We also have the capabilities to calibrate leak standards made by other manufacturers.

Once you are ready to have your leak standard re-certified, contact us with your CTS serial number(s), or if it’s a non-CTS leak standard, please also confirm original manufacturer, leak rate, pressure, and calibration gas. We will provide a formal quote and RMA document with return instructions.

Why You Should Choose CTS Leak Standards
Cincinnati Test Systems leak standards are manufactured and certified in our in-house lab in Harrison, Ohio. This enables faster lead times and assurance that our leaks are manufactured at the highest quality. We are A2LA ISO 17025 accredited and each leak standard comes with a certificate of calibration for your quality and audit requirements. If you misplace a certificate, no problem! Contact us for a PDF version. Each leak standard is serial tracked, with a history of its certifications in our database. This also makes it easier for you to request duplicate leaks.


The leak test experts at CTS can help you determine the right leak standard for your application.

Learn More About CTS Leak Standards >>