Regulators purchased prior to
August of 2004 were 1.5 liter per minute.
The Alco-Sensor FST requires a 6 liter per
minute flow rate to capture an automatic sample. (Manual samples
can still be taken with the 1.5 lpm barb if your local procedures
allow.)
The barb unscrews from the
side of the regulator.
Note the color of the barbs.
The 1.5 lpm barb is silver in color (left) while the 6 lpm barb is gold
in color (right).
While they look very similar
the difference is inside the barb. Here you can see the diameter
of the center hole that the vapor from your dry gas standard must travel
though to get to your instrument for testing.
The left (silver) barb
has an obvious smaller diameter hole and has the 1.5 liter per minute
flow rate. The right (gold) barb has a larger diameter hole to
allow the 6 liters per minute flow rate.
