The air purge option (Brookfield Part No.
KU-1A) allows the interior of the KU-1+ to
be pressurized with air (or an inert gas) when
the instrument is to be used in a hazardous
environment (Figure 2). A built-in pressure
switch turns the instrument off when the
pressure drops below 2.0 PSI (falling). The
switch comes on at 10.0 PSI (rising).
Connect a regulated clean air supply which
is non-corrosive to brass to the fitting shown
in Figure 2. Adjust the pressure to approximately
25 PSI.