HeMaTech Prüftechnik GmbH & Co. KG
Leak Testing Technology
Test Equipment, Methods, and Industrial Testing Technology
Leak Testing Technology from HeMaTech
Leak-tight components are a fundamental prerequisite for quality, safety, and reliable processes in numerous industrial applications. Whether it’s a valve, housing, pipe, container, or complex assembly: even small leaks can impair a product’s function and lead to scrap, customer complaints, or safety-related issues.
A professional leak test makes such leaks measurable. Modern leak testers enable reproducible tests and can be used both at manual test stations and in automated production lines.
However, the tester alone is not the decisive factor. Meaningful results arise from the interplay of leak testing technology, test procedures, test fixtures, adaptation, process parameters, and calibration.
HeMaTech Prüftechnik GmbH focuses precisely on this interplay. Its services range from leak testers and accessories to calibration and service, all the way to the development of custom test stations and automated test systems.
A professional leak test makes such leaks measurable. Modern leak testers enable reproducible tests and can be used both at manual test stations and in automated production lines.
However, the tester alone is not the decisive factor. Meaningful results arise from the interplay of leak testing technology, test procedures, test fixtures, adaptation, process parameters, and calibration.
HeMaTech Prüftechnik GmbH focuses precisely on this interplay. Its services range from leak testers and accessories to calibration and service, all the way to the development of custom test stations and automated test systems.
Reliably Check for Leaks
What is a leak test?
A leak test determines whether a component or system meets a specified leak-tightness requirement.
Depending on the test method, a change in pressure or a volume flow rate, for example, is measured.
Unlike a purely visual inspection, metrological leak testing provides quantitative and reproducible results.
Depending on the test method, a change in pressure or a volume flow rate, for example, is measured.
Unlike a purely visual inspection, metrological leak testing provides quantitative and reproducible results.
What does “tight” mean in industrial practice?
From a technical standpoint, “tight” is not an absolute state. Virtually every component can exhibit a certain degree of leakage if the measurement sensitivity is sufficiently high.
The decisive factor, therefore, is the permissible leak rate for the specific application.
The requirements vary considerably. A component that is sufficiently leak-tight for one application may fall significantly short of the requirements for another process.
Before selecting a test method, the following points, among others, must therefore be clarified:
The decisive factor, therefore, is the permissible leak rate for the specific application.
The requirements vary considerably. A component that is sufficiently leak-tight for one application may fall significantly short of the requirements for another process.
Before selecting a test method, the following points, among others, must therefore be clarified:
Only by analyzing these requirements can a suitable testing process be developed.
Any other questions about this?Why Leak Tests Are Important for Quality Assurance
A reliable leak test detects defective components as early as possible in the production process. This allows the causes of defects to be identified and leaky products to be removed before further value-added steps take place.
Reproducible test conditions are particularly important in mass production. The results should depend as little as possible on the operator or on changing environmental conditions.
This is precisely where automated leak testing technology offers a significant advantage.
Reproducible test conditions are particularly important in mass production. The results should depend as little as possible on the operator or on changing environmental conditions.
This is precisely where automated leak testing technology offers a significant advantage.
Accurately Detect Leaks
How does a leak tester work?
A leak tester creates defined test conditions and then monitors a measurable physical quantity. In pneumatic methods, this is often pressure or a pressure differential.
The basic test procedure can be divided into several phases.
The basic test procedure can be divided into several phases.
Test specimen, test pressure, and measurement phase
First, the test specimen is connected and sealed using a suitable device. It is then pressurized to the specified test pressure.
After filling, a stabilization phase may be required. The pressure and temperature must stabilize sufficiently to prevent incorrect measurement results.
Then the actual measurement phase begins.
The leak tester now monitors, for example, a change in pressure or a pressure differential. If the measured value exceeds the specified limit, the component is evaluated accordingly.
After filling, a stabilization phase may be required. The pressure and temperature must stabilize sufficiently to prevent incorrect measurement results.
Then the actual measurement phase begins.
The leak tester now monitors, for example, a change in pressure or a pressure differential. If the measured value exceeds the specified limit, the component is evaluated accordingly.
Why the test fixture is just as important as the test equipment
A high-quality measuring instrument alone does not guarantee a reliable testing process.
The entire measurement chain must be taken into account.
Test equipment → Connection technology → Test fixture →
Sealing → Test specimen → Process parameters
An unsuitable seal, unstable adaptation, or an inappropriately selected test volume can influence the result.
In industrial leak testing technology, therefore, one should not focus exclusively on the measurement accuracy of the device. The design of the entire test process is at least as important.
The entire measurement chain must be taken into account.
Test equipment → Connection technology → Test fixture →
Sealing → Test specimen → Process parameters
An unsuitable seal, unstable adaptation, or an inappropriately selected test volume can influence the result.
In industrial leak testing technology, therefore, one should not focus exclusively on the measurement accuracy of the device. The design of the entire test process is at least as important.
Overview of Testing Methods
What types of leak testing methods are there?
Various methods are available for industrial applications.
Which method is appropriate depends, among other things, on the component, the permissible leak rate, the test pressure, the cycle time, and the required sensitivity.
Which method is appropriate depends, among other things, on the component, the permissible leak rate, the test pressure, the cycle time, and the required sensitivity.
Pressure Drop Test
In the Pressure Drop Method A test volume is first brought to a defined pressure. The pressure is then monitored to see if and to what extent it changes within a specified time period.
Learn more nowA drop in pressure may indicate a leak.
The process is generally easy to understand and can be used in numerous industrial applications. However, when pressure changes are very small, the demands on sensor technology, process stability, and environmental conditions increase.
Differential pressure testing
Differential pressure testing is an important method in industrial leak testing and is also used in leak testers from HeMaTech.
This method does not rely solely on absolute pressure. Instead, the measurement technology detects very small pressure differentials within the test system.
This enables a highly sensitive assessment of leaks and is particularly well-suited for reproducible test sequences in manufacturing.
This method does not rely solely on absolute pressure. Instead, the measurement technology detects very small pressure differentials within the test system.
This enables a highly sensitive assessment of leaks and is particularly well-suited for reproducible test sequences in manufacturing.
Benefits for Industrial Mass Testing
However, to ensure reliable measurements, test volume, temperature, stabilization, and adaptation must also be taken into account here.
Learn more nowFlow-Based Testing Methods
Another option is to measure gas flow or volumetric flow . This method determines the amount of test medium flowing through the system as a result of a leak.
Such methods can be particularly useful when a leak needs to be evaluated directly as a flow rate.
The choice between pressure, differential pressure, and flow measurement methods should therefore always be based on the specific testing task.
Learn more nowSuch methods can be particularly useful when a leak needs to be evaluated directly as a flow rate.
The choice between pressure, differential pressure, and flow measurement methods should therefore always be based on the specific testing task.
Clean and non-destructive
Why Use Compressed Air for Leak Testing?
Pneumatic methods using air have become established for numerous industrial applications.
A key advantage is that testing can be performed dry and, as a rule, non-destructively. No liquid test medium remains in the component after the testing process.
This facilitates integration into production processes.
At the same time, automated processes with short test cycles are possible. Filling, stabilizing, measuring, evaluating, and venting can all be performed within a defined test program.
However, the actual cycle time depends heavily on the test volume, the required test pressure, the required measurement accuracy, and the component’s behavior.
A key advantage is that testing can be performed dry and, as a rule, non-destructively. No liquid test medium remains in the component after the testing process.
This facilitates integration into production processes.
At the same time, automated processes with short test cycles are possible. Filling, stabilizing, measuring, evaluating, and venting can all be performed within a defined test program.
However, the actual cycle time depends heavily on the test volume, the required test pressure, the required measurement accuracy, and the component’s behavior.
Technology for Practical Applications
What must an industrial leak tester be capable of?
When selecting a leak tester, one should not focus solely on individual technical specifications.
For industrial users, the most important factor is whether the device can be reliably integrated into the intended testing process.
For industrial users, the most important factor is whether the device can be reliably integrated into the intended testing process.
Measurement accuracy and reproducible results
A suitable system must reliably detect changes and deliver reproducible results under defined conditions.
At the same time, measurement accuracy should always be considered in the context of the actual test task. Higher theoretical resolution does not automatically offer an advantage if, for example, temperature changes, unsuitable fixtures, or fluctuating test conditions dominate the result.
At the same time, measurement accuracy should always be considered in the context of the actual test task. Higher theoretical resolution does not automatically offer an advantage if, for example, temperature changes, unsuitable fixtures, or fluctuating test conditions dominate the result.
Test Programs and Measurement Data Storage
In production environments, different component variants are frequently tested. Multiple test programs make it possible to define appropriate parameters for various products.
The storage and transmission of measurement results are also becoming increasingly important.
This allows test results to be documented, evaluated, and, if necessary, assigned to a component or production order.
The storage and transmission of measurement results are also becoming increasingly important.
This allows test results to be documented, evaluated, and, if necessary, assigned to a component or production order.
Interfaces for System Integration
In automated systems, the leak tester must be able to communicate with other systems.
Depending on the application, this may include digital inputs and outputs as well as industrial communication interfaces.
The tester thus becomes an integral part of a larger automation concept: feeding the component, clamping it, adapting it, testing it, transmitting the result, and then processing it further depending on the result.
Submit a Request NowDepending on the application, this may include digital inputs and outputs as well as industrial communication interfaces.
The tester thus becomes an integral part of a larger automation concept: feeding the component, clamping it, adapting it, testing it, transmitting the result, and then processing it further depending on the result.
Automate Testing the Smart Way
Leak Testing Technology in Automated Production Processes
As automation increases, the focus is shifting from individual measuring instruments to the complete testing system.
This is precisely where a key difference between a pure equipment supplier and a provider of industrial testing technology becomes apparent.
This is precisely where a key difference between a pure equipment supplier and a provider of industrial testing technology becomes apparent.
From a single leak tester to a complete leak testing system
In addition to the leak tester, a complete test station may include the following components, among others:
This transforms a single measuring device into a defined and reproducible production process.
Any other questions about this?Fixtures, Sealing, and Adaptation
Especially when dealing with complex component geometries, the adaptation plays a decisive role in determining the quality of the test.
Connections must be reliably sealed or connected to the testing system. At the same time, the fixture should be designed to be robust for industrial use and as easy to maintain as possible.
The development of such fixtures therefore requires both expertise in leak testing and experience in mechanical and plant engineering.
Connections must be reliably sealed or connected to the testing system. At the same time, the fixture should be designed to be robust for industrial use and as easy to maintain as possible.
The development of such fixtures therefore requires both expertise in leak testing and experience in mechanical and plant engineering.
Integration into automated production lines
HeMaTech combines leak testing technology with automation technology and, in addition to test equipment, also develops custom test stations and systems.
For users, this approach offers a decisive advantage: the test equipment and automation do not have to be considered in isolation from one another.
Instead, the entire testing process—from the test specimen through the measurement technology and adaptation to the control system and data transfer—can be designed as a complete system.
For users, this approach offers a decisive advantage: the test equipment and automation do not have to be considered in isolation from one another.
Instead, the entire testing process—from the test specimen through the measurement technology and adaptation to the control system and data transfer—can be designed as a complete system.
Ensuring Measurement Reliability Over the Long Term
Calibration of Leak Testers
Even a properly designed testing process must deliver reliable results over the long term.
Regular inspection and calibration of leak testing equipment play an important role in this.
Regular inspection and calibration of leak testing equipment play an important role in this.
Why Regular Calibration Is Important
Measuring instruments can change over time.
Therefore, it must be possible to trace how the values displayed by the test equipment relate to reference values.
Calibration provides a documented basis for this. There is no one-size-fits-all rule for how often calibration should be performed.
The interval depends, among other things, on usage, quality requirements, internal guidelines, and the criticality of the testing process.
Therefore, it must be possible to trace how the values displayed by the test equipment relate to reference values.
Calibration provides a documented basis for this. There is no one-size-fits-all rule for how often calibration should be performed.
The interval depends, among other things, on usage, quality requirements, internal guidelines, and the criticality of the testing process.
Leak Tester and Leak Calibrator
In addition to calibrating the measuring equipment, it may be advisable to regularly monitor the testing process.
Predefined test leaks or leak calibrators make it possible to introduce known leaks into a test setup.
This allows you to verify whether the system responds as expected.
This increases process reliability and helps detect changes early on.
Predefined test leaks or leak calibrators make it possible to introduce known leaks into a test setup.
This allows you to verify whether the system responds as expected.
This increases process reliability and helps detect changes early on.
Expertise from a Single Source
Leak Testing with HeMaTech Testing Technology
Industrial leak testing involves the interplay of many technical disciplines.
HeMaTech Prüftechnik GmbH therefore takes an approach that goes beyond the individual testing device.
The company offers leak testers for a variety of industrial testing tasks and combines them with customer-specific testing technology and automation.
Its range of services includes, among other things:
HeMaTech Prüftechnik GmbH therefore takes an approach that goes beyond the individual testing device.
The company offers leak testers for a variety of industrial testing tasks and combines them with customer-specific testing technology and automation.
Its range of services includes, among other things:
Added to this is our calibration expertise: HeMaTech operates a DAkkS-accredited calibration laboratory for pressure and flow.
This allows for a holistic approach to leak testing—from selecting the appropriate measurement method, through test equipment and setups, to automation, calibration, and service.
For technical decision-makers, it is precisely this comprehensive view that is important. After all, what ultimately matters is not just a precise measuring instrument, but a stable, reproducible, and cost-effective testing process.
This allows for a holistic approach to leak testing—from selecting the appropriate measurement method, through test equipment and setups, to automation, calibration, and service.
For technical decision-makers, it is precisely this comprehensive view that is important. After all, what ultimately matters is not just a precise measuring instrument, but a stable, reproducible, and cost-effective testing process.
Personalized advice
Submit a Request Now
Contact us—we’d be happy to advise you personally.
HeMaTech Prüftechnik GmbH & Co. KG
Siemensstr. 7
D-71409 Schwaikheim
FAQ - Practical Answers
Frequently Asked Questions About Leak Testing
What is a leak tester?
A leak tester is a measurement system used to detect and evaluate leaks in components or assemblies. Depending on the method used, measurements may include, for example, changes in pressure, pressure differentials, or flow rates.
How does a compressed-air leak test work?
A defined air pressure is applied to the test specimen. After a stabilization phase, the testing device monitors a relevant measurement parameter. Based on defined limit values, an assessment is then made as to whether the test specimen meets the leak-tightness requirements.
What leak testing methods are available?
Methods used in industry include, among others, pressure drop, pressure rise, differential pressure, and flow rate methods. In addition, there are other methods designed for specific requirements. The appropriate method depends on the specific test task.
What is a differential pressure test?
During a differential pressure test, very small pressure differences within a test system are measured. This allows one to determine whether a leak is present and, if so, its extent.
How accurate is a leak tester?
The achievable accuracy depends on the device and measurement method used, as well as on the test pressure, volume, temperature, measurement time, and test setup. Therefore, accuracy should always be evaluated for the specific application.
How often should a leak tester be calibrated?
There is no universally applicable calibration interval. It should be determined based on usage, the required process reliability, the company’s own quality standards, and, where applicable, regulatory or customer-specific requirements.
A Holistic Approach to Water Tightness
The Right Testing Technology for Reliable Leak Tests
A reliable leak test cannot be achieved by the testing device alone. Measurement methods, test parameters, equipment, adaptation, automation, and calibration must all be coordinated.
That is why, especially in automated production processes, it is worthwhile to take a holistic approach to the inspection task.
The HeMaTech Prüftechnik GmbH combines leak testing equipment and measurement technology with calibration expertise, fixture design, and automation. This enables the company to implement both individual testing tasks and complete industrial leak testing systems.
Anyone looking to optimize an existing leak test or find a suitable leak test device , or develop a new automated testing process should therefore take the entire measurement and process chain into account right from the planning stage.