The Pioneer of Modern Leak Testing

How to Buy Leak Testing Equipment

Leak testing is a critical aspect of the quality control process for a wide range of products. As manufacturers evaluate the many types of leak testing equipment available today, they must consider a long list of variables that go well beyond whether a leak tester can handle a specific application. 

Whether it’s using a tablet with the full capabilities of a computer or a smartphone that empowers us to consume information wherever we are, technology and innovation have changed the way we conduct business and make decisions. Advanced manufacturing processes – such as those found in medical device, automotive, and packaging industries – have been heavily impacted not only by technology, but also by new regulations that have been developed in response to the ways technologies are being used.

This article guides you through the information you need and the questions you should ask before buying a leak testing equipment.

What is Automatic Leak Testing Equipment?

USON Innovative Systems (UIS).Automatic leak testers perform tests without operator attention or interpretation. Today’s advanced manufacturing standards demand sophisticated product testing, data intelligence and management, and compliance with the latest communication protocols. Even basic leak testing applications require:

  • Specialized testing techniques
  • Various test pressures or vacuum levels
  • Multiple programs for various parts to be tested
  • Multiple testing either sequentially or simultaneously

A complete test cycle performs one or multiple tests from start to finish, displaying quantitative results with accept and reject status. Accept and reject limits are programmable. Common leak tester types:

Automatic production leak testers typically perform leaks tests in 0.2 seconds to 30 seconds. These testers easily communicate with programmable logic controllers (PLCs). Common capabilities include:

  • Storing test data
  • Monitoring and logging trends
  • Collecting, reporting, and archiving data
  • Offering security features, including password protections and customizable user authorization
  • Incorporating self-maintenance programs
  • Changing test programs automatically
  • Compensating for temperature changes
  • Automatically compensating and calibrating
  • Alarming out-of-calibration conditions
  • Providing multiple station and multiple pressure capability

What Should I Look For in a Leak Testing Equipment Supplier?

Evaluation checklist for a leak testing supplierBe sure you select a leak tester supplier who has diverse experience and a proven record of success, and who offers leak testing techniques that exactly match your application and requirement. At a minimum, your leak tester supplier should offer and support a wide variety of test techniques, including:

*Most common because of ruggedness and simplicity

With these techniques available, your supplier can thoroughly evaluate your requirements and recommend ideal techniques for your specific applications. Remember, the purchase of a quality product from a qualified and trusted supplier comes with security and guaranteed performance.

Look for quality registrations, such as:

  • ISO 9001
  • CSA (Canadian Standards)
  • CE MARK (European Standards)

These registrations help ensure additional overall quality, documentation, and validated software.

Are Leak Tester Resolution and Sensitivity Important?

Sensitivity and resolution should be among your major considerations when purchasing a leak tester. But they should be reviewed in the context of your manufacturing goals and quality requirements. Be sure you consider a complete system, as well as long-term repeatability and stability of the test instrument.


When evaluating leak testers, you might see resolution claims such as .0001 psi or better. Be aware this resolution could merely reference analog-to-digital converters operating under ideal conditions, without noise, and without connection to the real world.

While raw resolution numbers might be true, they are often not usable figures. To determine usable resolution, it is important to consider the entire system: electronics, sensors, pneumatic components, and the environment in which the test system will be used. Only then will you see the true picture of system resolution.


When you hear claims such as .01 cubic centimeters per minute leak sensitivity, be skeptical. While that sensitivity might be achievable, it might only be achievable in a few applications.

As with resolution, the true testing sensitivity depends on the total system, including your part and test specifications.

Purchasing a leak tester based on exaggerated claims of resolution and sensitivity can be a costly mistake.

Leak Tester Cost Considerations

Leak tester cost considerationsYou should never buy a leak tester based solely on price. Many factors should be considered besides initial cost.

If you buy on price alone, you should also budget additional time and money for potential failure and ongoing problems. If you can afford to do this, you can probably afford to purchase a quality leak tester from the beginning. For example, say you save several thousand dollars on your leak test machine’s initial purchase, this seemingly large savings can rapidly cost you in:

  • No local support
  • Poor performance
  • No telephone support
  • Extra cost for training
  • Non-repeatable results
  • Continuous breakdowns
  • Poor or inadequate manuals
  • Inadequate applications support
  • No emergency parts availability
  • Extra cost for installation assistance
  • Lack of flexibility for changing needs
  • Calibration failures and product recall
  • Poor software maintenance and documentation

You cannot analyze tester cost by the formula that lower purchase price equals lower cost. Always consider the long-term value you will receive over years of ownership, and your partnership with a successful and innovative supplier.

What About Tester System Flexibility?

One of the most important considerations in buying a leak tester is flexibility. Experienced users have long recognized the need for flexibility built into well-designed leak testers. Flexibility is added to well-designed leak and flow testers for good reason. Although built-in flexibility may increase initial cost, flexibility has potential to save considerable amounts of time and money over the system’s lifetime.

In the beginning stages of the specification process, there is a tendency to think you only need a go, no-go tester. Later on, however, you might have specification changes, new products, or product variations that will require different types of testing. For example, many manufacturers realize the value in being able to qualify test results, collect data, and perform active statistical analysis. Other important features that might be needed include LAN compatibility, bar code reading, temperature compensation, or other analog inputs.

As requirements change and increase, the need for solid software maintenance and documentation, good manuals, and training support provided without hidden charges becomes exponentially important.

What Does Supplier Need From Me?

If you have testing parameters, provide them to your supplier. These facts will be important to your supplier:

  • Test volume
  • Reject leak rate
  • Test part description
  • Part numbers of all items to be tested
  • Part material
  • Test pressure
  • Production rate

If test parameters are not available, explain your application and challenges to your leak test supplier. Your supplier should have years of application experience to help you set parameters and select a system that’s right for your application. For a new product, certain variables should be considered when setting leak test specification. Answers to these questions will be helpful:

  • Working pressure of the product
  • Type of liquid or gas used in the product
  • How your product is used in the marketplace
  • Material from which the product is constructed
  • Whether the seal must prevent liquid or gas leakage
  • Consequences of leakage or improper flow, such as:
    • Cost to the user
    • Product malfunction
    • Product deterioration
    • Possible fire or explosion
    • Frustration or inconvenience
    • Harm to people or surroundings
    • Unsightly or displeasing environment

Uson’s Leak Testing Experts Can Help!

If you’re in need of leak testing equipment, our team of experts can help with tester selection, application and feasibility studies and much more.  Contact us today or find a Uson representative in your area. 

Contact Us


Uson L.P. - Corporate

8640 N. Eldridge Parkway
Houston, TX 77041 USA

Tel: +1-281-671-2000
Fax: +1-281-671-2001


Uson UK – Europe

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Bury St. Edmunds
Suffolk, IP33 3SP United Kingdom

Tel: +44-1284-760606
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Uson – China

Room 601, 567 Lan Gao Road
Shanghai, 200333, China

Main: 021-583 65859, 021-583 59187
Fax: 021-583 59185, 021-337 73559