The PHD-4 is a portable, compact leak detector which can detect very small leaks in objects that have a slight helium/air pressure inside. It is sensitive to helium concentrations as small as 2 parts per million (three orders of magnitude greater than the industry standard). That is equivalent to a leak rate of 5 × 10-6 atm-cc/sec, which is far superior to the performance of other means of detecting leaks, such as bubble-testing.

Controlled by a microprocessor and using a touch-screen for input and output, the PHD-4 is easy to use. No training is required. All tuning and zeroing are handled automatically. The display can be set to use any of four languages (English, French, German, and Italian). And with a battery life of up to four hours, and weighing only 5.7 lbs. (2.6 kg) including the battery, the PHD-4 can be taken anywhere.

The PHD-4 uses patented Selective Ion Pump Detection (SIPD) technology. The sensor incorporates a quartz capillary tube maintained under high vacuum by an ion pump. The quartz tube is heated with a platinum filament and becomes permeable to helium. As the partial pressure of helium in the ion pump increases, so does the current drawn by the ion pump, proportional to the pressure, indicating the helium concentration present in the test probe of the PHD-4.

Helium is a superior choice as tracer gas for a number of reasons...

• It is inert, non-toxic and non-flammable
• It easily passes through leaks due to its small atomic size, allowing detection of very small leaks
• It is highly mobile, allowing rapid desorption and short measurement times
• It is present in the atmosphere at only 5 ppm, thus reducing the possibility of false readings

Large vessels and bioreactors

• Heater exchangers and steam condensation line
• Water pipes
• Radiant heating systems

The PHD-4 allows leak location without interruption of the normal operation, by mixing helium with the water in the circuit. Until recently, the precise and rapid location of leaks in buried pipes has been very difficult.

In the event of a leak, helium desorbs from the fluid and diffuses to the surface, where it is easily detected. Leaks in pipeline systems such as district heating systems, drinking or chilled water systems and steam pipe networks incur high costs due to losses and corrosion damage.

Water heating and cooling pipes

• Fermenters
• Sterilizers
• Freeze dryers

The PHD-4 offers unmatched accuracy and repeatability, presenting a unique solution that it is cost effective and very well suited for the leak range specifications of this application.

Biotech and pharmaceutical industries used to rely on pressure decay and bubble test methods for finding leaks in their large bioreactors. The PHD-4 has established a new standard of quality, significantly increasing production yields.

Some of the features of the PHD-4 include...

• Autozero function, which allows leak detection even in high helium background environments
• Excellent selectivity for helium allows you to read helium leaks and ignore all other gases
• Ready for testing in less than three minutes
• Wide range of applications, meaning it can replace or be used alongside existing methods such as bubble test or pressure decay
• CE, CSA/US approved for global standardization

The PHD-4 is in daily use in many other applications besides the ones described above. Virtually any object requiring any level of leak tightness can be simply tested with this instrument. For details on these other applications for the PHD-4, as well as a complete technical specification, please download our PDF brochure below.

Should you have any questions, or if you would like to discuss any of this further, then please do not hesitate to get in touch.