Small improvements concerning helium measurement. Using different barometric pressure sensor. Available with rechargeable battery only.

These models have a new amber OLED display with improved readability. Type 2.4 have a barometric sensor for automatic ambient pressure correction and can be equipped with LiIon accumulator. The user's manual is available in PDF format. Current version dates from July 2012.

These models have an LCD display with backlight. Type 2.2 has some supplemental signals connected to the rear system connector. The user's manual is available in PDF format. Current version dates from 27 May 2008.

The user's manual is available in PDF format. Current version dates from 16 November 2004.