General Description
The 720b is an advanced state-of-the-art leak
detector capable of detecting many combustible,
noncombustible and toxic gases.
The following is a partial list of gases that the
720b is sensitive to:
Acetone, Alcohol, Ammonia, Steam, Carbon
Monoxide*, Butane, Gasoline, Jet Fuel, Hydrogen
Sulfide, Smoke, Industrial Solvents, Methane,
Lacquer Thinner, Naphtha, Propane, Natural Gas.
*Not to be used to quantify the amount of CO
present.
Operating Instructions:
1. Turn the unit on in an uncontaminated
environment (clean air away from the system in
question) by moving the switch from the
OFF position to the ON position.
2. The GREEN ready light will illuminate if there is
ample battery power. The RED LED may
flicker and the tick may sound during the
warm-up. To silence the tick, rotate the thumb
wheel fully counterclockwise.
3. Adjust the TICK ADJUST by rotating the thumb
wheel in a clockwise direction until a uniform
ticking sound is heard. The RED light will flash
at the same time the tick sounds.
4. Approach suspected leak areas with the sensor
until the tick begins to increase. When the tick
increases, do not move the sensor from the area,
rotate the TICK ADJUST slightly counterclock-
wise to slow the ticking and continue to
approach the suspected leak area with the sen-
sor. Continue to slow the tick until the location
of the leak is found. If the tick stops, the con-
centration level has decreased. Move back in the
opposite direction to find the leak again.
5. If the GREEN LED changes to orange color,
change the batteries.
6. An earphone can be plugged into the earphone
jack when using the instrument in noisy environ-
ments.
9. If the instrument does not perform or it has been
damaged, follow the Operation Check section of
this manual.
Battery Replacement
1. Remove the battery compartment cover from the
bottom of the handle by sliding the door away
from the front side of the instrument.
2. Remove the batteries and replace by sliding the
