Garnet SeeLevel I 705 Series Manual page 8

4. There is no hold mode for the LPG. The LPG tank level cannot change
fast enough to justify the use of the hold function, except during filling of
the tank. The gauge should not be used as a full tank shutoff indicator
since the LPG sender in the tank is not reliable or accurate enough to be
used as a safe indicator of a full tank.