Leak Detection with Tracer Gases

The answer to all your leaks, no matter how big or small: Our tracer gas leak detectors are designed for a wide range of applications and requirements. The portfolio ranges from lightweight and portable to modular and sniffer units.

Efficient leak detection: advantages and requirements

of test gases such as helium and hydrogen

To be used for proper leak testing a tracer gas has to fulfill several requirements, for example a low ambient concentration, a high sensitivity detector technology and a non-toxic character. These requirements are fulfilled by Helium as well as Hydrogen (as “forming gas” in the concentration 95% N2 and 5% H2). The most common tracer gas in the field of leak detection and leak-tightness testing under vacuum is Helium. It is safe and a small, light molecule which is suitable for detecting micro leaks. The detection range of Helium in vacuum tests lies between 10-1 and 10-12 mbar · l/s. Helium leak detection is extremely accurate, quantitative and repeatable. Fast cycle times are a further advantage.

Manual sniffing or spraying is often the easiest way to detect a leak with Helium. But it is also possible to use automatic leak detection solutions which are independent of the operator and provide a considerably higher detecting speed. The integral leak detection is designed to achieve pre-defined quality and component throughput levels.

The use of tracer gas leak detection methods has the bonus of delivering additional data compared to traditional leak detection methods such as bubble testing. These data like a quantified leak rate, analysis of signal evolutions together with precise monitoring of test parameters can be used to improve production processes and successfully detect every leak.

Brochure cover tracer gas leak detectors

Brochure: Tracer gas leak detectors

Portable leak detector ASM 310

Compact, lightweight and portable

The ASM 310 is our answer to the requirements of maintenance tasks where mobility plays a major role. For these applications it is important that the leak detector used has compact dimensions, is lightweight and portable. Our ASM 310 portable leak detector weighs 21 kg, less than half the weight of standard units. It has a universal mains connection and is therefore ready for use anywhere in the world. Accessories include a dedicated trolley for better mobility and a carrying case that allows the unit to be taken on an airplane for worldwide service calls.

The ASM 310 is equipped with a high-resolution graphical color display and can be easily controlled via a detachable control panel or with a remote control, even from a distance. The menu navigation is user-friendly and easy to operate.

Highest performance

Despite its light weight and compact dimensions, the ASM 310 is a complete tracer gas leak detection unit equipped with the same detector technology and offering the same sensitivity as larger models. The clean, oil-free pumping system makes the ASM 310 the right choice for leak detection on systems that do not tolerate any contamination. The ASM 310 can be operated in any position and offers unrivaled performance for leak testing when mobility is key.

Easy documentation of your leak detection process

The intuitive menu can be customized and password protected. This prevents unauthorized changes to the settings. Thanks to the high capacity of the internal memory, the ASM 310 offers the option of documenting leak detection results in the form of image or text files. In addition, data, test configurations and operating parameters can be downloaded or transferred to other devices via a dedicated USB port.

Customer benefits

  • Oil free pumping system, roughing capacity 1.7 m3/h

  • Ultralight, only 21 kg (46 lbs) and easy to move

  • Smart design with retractable handle

  • Operable in any position (horizontal or vertical) with intuitive and customizable menu

  • Removable, magnetically positionable control panel with large, bright color touchscreen and graphics function

  • SD card as a storage option (bitmap or text files) for easy post-processing of the leak test results


  • Semiconductor and coating industry

  • Medical

  • R&D

  • Power plants and chemical plants

Multipurpose leak detector ASM 340

Reliable and high-performant

The leak detectors in our ASM 340 series guarantee top performance in vacuum or sniffing leak detection for various applications, from maintenance to applications in small production environments. These dependable leak detectors can be used both for qualitative localization of leaks as well as quantitative global or local testing. They are the only leak detectors in their class offering qualitative leak detection starting at 100 mbar before reaching the inlet test pressure.

The ASM 340 is characterized by its powerful pumping system and available in conventional or dry versions. Easy operation, ultra fast response time and short recovery time are among the outstanding features of these compact multipurpose units. The ASM 340 is the perfect solution for everyday testing even in severe test conditions.

Easy operation and smart functions

The control panel is equipped with a large, bright and high-resolution color touch display that offers a new user experience. Therefore, no training is required to operate the ASM 340. The configuration of your leak test is directly accessible on the main screen and and the color management of the display improves the readability of the test results. The control panel is removable with integrated magnets, which improves ergonomics when leak testing of medium or large parts.

The ASM 340 has an integrated SD memory card for setting up your individual parameters as well as recording and downloading your leak detection results. In addition, all models of the ASM 340 series can be equipped with communication options. From I/O to fieldbus options, a comprehensive selection is available.


Customer benefits

  • Fastest time to test in its class

  • High backing pump capacity for versatile use

  • Rapid response time due to high helium pumping speed

  • Unique capability to detect leaks starting at 100 mbar

  • Impressive results in sniffing test mode, with 5 · 10-9 mbar · l/s minimum detectable leak rate for helium

  • Low maintenance due to rugged design


  • R & D

  • Aeronautic industry

  • Mechanical engineering

  • Measuring technology

  • Refrigeration

  • Air conditioning

  • Semiconductor technology

  • Leak detection systems

High performance & mobile leak detector ASM 390/ASM 392

Rapid pump-down and short response times for large test objects

The ASM 390 and ASM 392 are the perfect leak detection solutions adapted to the semiconductor and display industries as well as other demanding applications where rapid pump down and high sensitivity is key. Both units are fully Semi S2 compliant.

These leak detectors are fitted with a dry frictionless backing pump and a powerful high vacuum pump, making them the ideal tools for leak testing of various components in clean environments. Equipped with an additional turbopump, the ASM 392 will speed up your leak detection process to reduce downtime of your production equipment.

Leak detector ASM 390 and ASM 392 in 3D

Leak detector ASM 390 and ASM 392 from Pfeiffer Vacuum in 3D

Ergonomic and highly maneuverable

ASM 390 and ASM 392 share the same platform and are uniquely ergonomic with a convenient size and height, a secondary handle in the front, a fully rotatable, removable display, an inlet in the front for easy connection to test ports and unrivaled maneuverability for access to all testing areas, even in tight spaces.

Smart and user-friendly

Thanks to a wide, clear color touch display panel, an integrated toolbox with modular compartments and storage space for vacuum bellows, you will be amazed how easy leak detection can be when you have all necessary accessories at the point of use.


Customer benefits

  • Superior leak testing performances

  • Intuitive menu and large, rotatable touch-panel color display

  • High roughing capacity (35 m3/h) for fast evacuation

  • Dry and clean pumping technology

  • Low maintenance requirements

  • Ergonomic design with working surface

  • Fast recovery in case of pollution

  • Integrated toolbox for storage of accessories

  • Fast start-up

  • High sensitivity and accurate measurements

  • Fully Semi S2 compliant


  • Semiconductor industry

  • Large area coating

  • Solar industry

  • Accelerators

  • Laser technology

  • Ultra-pure media supply

  • Electronics

  • Aeronautics

  • Medical technology

Modular leak detector ASI 35

Quick and easy integration

The modular leak detector ASI 35 is designed for integration into industrial leak detector systems. It can be flexibly adapted to a wide range of leak detection applications and environments in the production of electrical and mechanical parts. With helium or hydrogen as tracer gas, the ASI 35 offers excellent performance for integral and localizing test methods or a combination of both.

The modular design and small footprint of the ASI 35 enables it to be easily integrated into existing systems. A particular feature is the leak detector's ease of use. Its high reliability and short maintenance times are crucial for avoiding production downtimes and quality problems.

Flexible and reliable

The ASI 35 modular leak detector is specially adapted to meet the requirements of machine builders, system integrators and their end users. The vacuum module with its analyzer cell and calibrated test leak can be installed in any position. The electronic module and the optional control panel are ready for inserting in half 19" racks. They can be fitted in any part of the system or in a cabinet under controlled environmental conditions. The leak detector can be controlled without a control panel simply through a PC or PLC as it has a wide range of interfaces and complies with all industrial standards. The rugged design of the ASI 35 ensures long-term maximum availability of the unit under production conditions.

Customer benefits

  • Integral and localizing test (vacuum and sniffing) for both tracer gases: helium and hydrogen

  • Short cycle times due to highest pumping speed

  • Maximum reliability and robustness for high uptime

  • Wide temperature range allows for operation in challenging environments

  • Worldwide operation thanks to universal voltage of the electronic module

  • Ability to sustain up to 800 sccm flow in sniffing applications

  • Easy substitution of any other modular leak detector model (I/O compatibility mode)


  • Automotive

  • Refrigeration and air conditioning

  • Packaging

  • Mechanical parts

Sniffing leak detector ASM 306 S

Powerful, fast and compact

The sniffer leak detector ASM 306 S will help you to meet your daily challenges for leakage control using sniffing measurements in emerging technology like e-mobility and hydrogen energy economy or well established applications in refrigeration and air conditioning. The ASM 306 S offers all the advantages of a proven technology regarding sensitivity, accuracy and repeatability. It has been designed to offer fast and repeatable measurements, whether helium or hydrogen is used as tracer gas. This unit offers the highest testing reliability to increase productivity and quality levels and provides the fastest recovery in case of big leaks to maximize uptime. Additionally specific attention has been placed on the robustness of the complete ASM 306 S, including the probe and its cable, to provide you a full-time sniffing unit with low cost of ownership.

ASM 306 S – helium and hydrogen sniffer leak detector

ASM 306 S – helium and hydrogen sniffer leak detector

Smart and user-friendly

The display of the ASM 306 S offers easy readability with its large size, fully tactile and high resolution screen. Co-designed with the user in mind, the ergonomics of the sniffer probe has been a major focus allowing the operator to be able to hold the sniffer probe during their entire working shift. The test information is visible directly on the probe for easy visual management, so operators can focus on test parts. The high flow probe will help you pinpoint leaks easily without missing any of them. The probe can be equipped with various hose lengths to easily adapt to your application and can be exchanged independently from the probe itself.

The ASM 306 S can be completed with a 2 years lifetime calibrated leak with both helium and/or hydrogen.

Customer benefits

  • Helium and hydrogen tracer gases

  • High sensitivity and accurate measurements

  • Intuitive menu for easy operation

  • Fast start-up

  • Fast recovery in case of pollution

  • Compact design and small footprint for easy integration into your production line

  • Integrated toolbox

  • Latest generation of tactile HMI with a large touch screen

  • Low maintenance requirements


  • Cooling systems such as refrigerator and air conditioner

  • Heat exchangers

  • Valves and manifolds

  • Gas circuit components

  • Storage tanks, expansion vessels