Faster Leak Detection with the Modul1000 Helium Leak Detector

To achieve a faster pump down time, usually expensive changes in your leak detection system are necessary. With the INFICON Modul1000 there is an easy-to-install and inexpensive way to improve your leak detection operation.

In a typical leak detection application a volume like a small vacuum chamber or a test item is pumped down by the vacuum leak detector. Inevitably, the pumping speed of the fore pump is reduced by the conductance of the leak detector.

The correlation between pumping speed and pump down time is given by:

It should be noted that in real applications, the time will be longer than calculated because at low pressures the effective pumping speed decreases. This fundamental behavior is different for pumps of various sizes and types.

In order to minimize the reduction of pumping speed, a by-pass valve can be added between the volume to be pumped down and the leak detector. The partial flow valve should be attached via a flexible hose with the vacuum system to avoid hammering of the valve against the inlet port of the leak detector.

Fig. 2 shows the pump down times for a 5-liter-volume with and without by-pass. The measurement cycle starts with 1013 mbar in the volume. At 0.4 mbar, the Modul1000 starts with the leak rate measurement. With the by-pass, the effective pumping speed at the volume is much higher than without by-pass, so the pump down time is reduced by a factor of 4!

The INFICON Modul1000 Leak Detector supports the operation of a partial flow valve. To control the valve by the Modul1000, the leak detector interface can be easily configured via the control unit or RS232.