INDICATOR OF LEVEL OF LIQUID WITH TEMPERATURE-SENSITIVE RESISTORS Russian patent published in 2002 - IPC

FIELD: indication of level of fuel in fuel tanks of aircraft. SUBSTANCE: indicator incorporates two temperature-sensitive resistors connected in series installed in level gauge located in fuel tank. Temperature-sensitive resistors have temperature coefficients of resistance of same sign, different gas parameters of convective heat exchange and equal rated resistance. Temperature-sensitive resistors are connected to power supply source. Indicator has controlled double-position switching key, each immobile contact of key is connected to one of temperature- sensitive resistors and switching contact is connected to input of analog-to-digital converter which body is grounded, for instance, is connected to fuselage of aircraft. Output of converter is connected to input of divider ad output of the latter is linked to measurement input of comparator whose reference input is coupled to output of source of reference signal and whose output is connected to input of indictor. Control inputs of controlled key and divider are connected to output of generator of controlling pulses. Common point of temperature-sensitive resistors is grounded. EFFECT: ruling out the possibility of generation of false signal on absence of liquid while indicator operates in wide range of uncorrelated temperatures of liquid and gas. 1 dwg