The ASM 390 high-performance mobile helium leak detector is fitted with a powerful ACP 40 (35 m3/h ) dry rotary lobe backing pump. This makes it the ideal solution for maximum testing sensitivity in analytics, laboratories, and the solar panel & semiconductor industries. With the ASM 390, you will achieve extremely short pump down times even where large volumes are involved. The slim design and compact size set up on a cart with large wheels and a low center of gravity make this leak detector mobile and safe to handle. They can be used for both vacuum and sniffer leak detection with helium (4He, 3He) and hydrogen (H2). The minimum detectable leak rate available for this unit in vacuum mode is 1x10-12 mbar l/s and in sniffer mode 1x10-8 mbar l/s.
The ASM 390 with its low noise level of only 55 dB(A) is unusually quiet for a leak detector of its class. The color display panel with full 360° viewing can be read from any position. This display is also detachable and can be positioned where the user can see it using four strong magnetic clips. An integrated SD memory card makes it easy to save test data and settings parameters. The ASM 390 has an integrated lockable toolbox for tools, spare parts and accessories. Thanks to its convenient bottle-holder, it is even possible to attach and carry a tracer helium gas bottle. Compatible with the wireless remote control RC 500 WL. This enables the leak detector to be operated even from a distance of up to 100 meters. The ASM 390 is the perfect solution for high sensitivity helium leak testing in very large systems and installations . The operating Instructions for the ASM 390 can be downloaded by scrolling down to PDF documents below.
FEATURES of the Pfeiffer Adixen ASM 390 Helium Leak Detector:
- Min. detectable leak 1x10-12 mbar
- 10 l/s helium pumping speed
- High Roughing Capacity, 28 CFM (35 m3/h ) Dry ACP Backing Pump
- Fast time to test: unrivaled performances from small to large volumes
- High maneuverability and compact design
- Superior leak testing performances
- Large rotateable color touch screen
- Dry and clean pumping technology
- Low maintenance requirements
- Ergonomic design with working surface
- Fast recovery in case of pollution
- Intuitive menu for easy operation
- Integrated toolbox for storage of accessories
- Fast start-up
- High sensitivity and accurate measurements
- Fully Semi S2 compliant
Optional ACCESSORIES for The Pfeiffer Adixen ASM 390 Dry Helium Leak Detector Cart System:
- Bottle holder, PN: 118444
- Helium Spray Gun, PN: 112535
- Helium Sniffer Probe, PN: SNC1E1T1
- Standard Remote control (wired), leak rate in Torr l/s, legend in English, PN: 108881
- Remote Control RC 500 WL (wireless), PN: PT 445 432-T
Helium Leak Testing Basics
Helium mass spectrometry, or helium leak testing, is a highly precise means of leak detection. This technology was first developed for the Manhattan Project during World War II to locate extremely small leaks in the gas diffusion process.
At the heart of helium leak testing is a complex piece of equipment called a helium mass spectrometer. Quite simply, this machine is used to analyze air samples (which are introduced into the machine via vacuum pumps) and provides a quantitative measurement of the amount of helium present in the sample. In practice, a "leak," is identified by a rise in the level of helium being analyzed by the machine.
Helium leak testing can identify extremely small leaks. For example, our equipment can detect a leak so small that it would emit just two cubic centimeters of helium (or the amount equal to two sugar cubes) in 320 years. While very few applications require this level of precision, this example serves to highlight the accuracy possible with this process.
While helium leak detection may appear to be a simple procedure, the process involves a combination of both art and science. The user must ensure the equipment is functioning properly and the process is highly dependant upon the user’s experience. Consider this analogy: while anyone with enough money can buy an airplane, learning how to fly one takes a lot of practice. The same is true with helium leak detection-make sure your "pilot" knows how to fly.
Why Is Helium Superior?
While many gases are used in leak detection, helium’s qualities provide for superior testing. Having an AMU (Atomic Mass Unit) of only 4, helium is the lightest inert gas. Only hydrogen, with an AMU of 2, is lighter than helium. However, due the hydrogen’s explosive potential it is rarely used.
Additional reasons why helium is a superior tracer gas:
- Only modestly present in the atmosphere (roughly 5 parts per million)
- Flows through cracks 2.7x faster than air
- Nontoxic
- Nondestructive
- Nonexplosive
- Inexpensive
- User Friendly
Due to these attributes, and its high sensitivity, helium leak testing has gained broad acceptance in a wide range of leak testing applications. Helium Leak Testing’s two primary testing modes while there are a variety of testing procedures, in general there are:
Two primary methods of helium leak testing:
- Spray Probe
- Sniffer Probe
The choice between these two modes is based on both the size of the system being tested, as well as, the level of sensitivity required.
Spray Probe: Provides Maximum Sensitivity
For this technique, the leak detector is hooked directly to the system under test and the inside of the system is evacuated. Once an acceptable vacuum is achieved, helium is sprayed discreetly on the outside of the system, with particular attention being paid to any suspect locations. Any leaks in the system, including defective welds (caused by cracks, pin holes, incomplete welds, porosity, etc.), flawed or missing gaskets, leaks due to loose clamps, or any other defect will allow helium to pass and be readily detected by the machine. The source of any leaks can then be accurately pinpointed and repaired.
The spray probe process is used to achieve the highest level of sensitivity. The equipment being used dictates the maximum sensitivity achievable; in Jurva Leak Testing’s case it is 2x10-10 std cc/sec. This technique does require that the system being tested is relatively leak tight prior to testing, as an ample vacuum is required for testing. However, by using special throttling devices a gross test can typically be performed. The gross test should eliminate any major leaks, permitting the use of increased sensitivity.
The following are examples of systems that we test using the spray probe technique:
- A-bar furnaces
- E-beam systems
- Laser systems
- Metal deposition equipment
- Distillation systems
- Vacuum systems
Sniffer Probe
For this technique, helium is purged throughout the inside of system being tested. Due to the innate properties of helium it readily migrates throughout the system and in its attempt to escape penetrates any imperfections, including: defective welds (caused by cracks, pin holes, incomplete welds, porosity, etc.), flawed or missing gaskets, leaks due to loose clamps, or any other defect. The system’s exterior is then scanned by using a probe attached to the leak tester. Any leaks will result in an increased level of helium nearest the source and be readily detected. Leak sources can then be pinpointed, providing the opportunity for immediate repair and retest.
Unlike the spray probe technique, this process is very flexible and can be adapted to meet the needs of any virtually any system in which helium can be injected. There is no practical size limitation. The sniffer probe technique is not as sensitive as the spray probe process, however, due to the amount of helium present in the air (approximately 5 ppm). The maximum sensitivity achievable under this procedure is approximately 1x10-6 std cc/sec. Nevertheless, this process is vastly superior to other traditional leak testing methods, such as: bubble testing, acoustic emission, liquid penetrant or vacuum box testing.
The following list is an example of systems that Jurva Leak Testing has tested using the sniffer probe process:
- Storage tanks (both above ground and below)
- Floating roofs
- Underground pipelines
- Underground cables
- Aseptic systems (flash coolers, heat exchangers, fillers, etc.)
- Any vessel/line or system that can be pressurized
Pfeiffer ASM 390, 392 Helium Leak Detector Operating Instructions.pdf
