You May Have Noticed the 'S' Added to Models GT-526, BT-637 and Aerocet-531.

'S' Versions Introduced at AAAR Meeting in Portland, Oregon

The ‘S’ was added to models GT-526, BT-637 and AEROCET 531 when we upgraded the electronics to include:

·              User selectable sizes (GT-526S and BT-637S)

·              USB communication (all)

·              LI-Ion batteries (all)

·              Count alarms (GT-526S)

·              Extended serial commands (all)

·              Keyboard controls for flow and display contrast (the older units have pots). (all)

·              Additional sizes (AEROCET 531S)

·             1 minute sample time (AEROCET 531S). The non-S takes 2 minutes.