(under subclass 290) Gauges having electrode means exposed to the liquid whereby said liquid may complete the circuit between said electrodes as it rises. There may be a plurality of pairs of electrodes at different elevations or a linear resistance spaced from a conductor and bridged by the fluid to change the resistance by increments upon change of liquid level.
SEE OR SEARCH THIS CLASS, SUBCLASS:
301, for immersible electrode gauges employed in connection with pressure responsive liquid level gauges.
313, for other combinations with electric signals.
SEE OR SEARCH CLASS
324, Electricity: Measuring and Testing, 425+, for electrolytic testing and subclasses 600+ for the measuring of impedance.
338, Electrical Resistors,
38, for a liquid resistance element or contact operated by a change in fluid or gas pressure. See the reference to Class 338 under (3) Note, C, above.
340, Communications: Electrical,
620, for a nonquantitative liquid level alarm having an electrode probe.