Abstract: An apparatus for distinguishing a liquid reducing agent which judges empty with a higher precision than heretofore is provided. The apparatus for distinguishing a liquid reducing agent is provided with a concentration sensor and a liquid-level sensor in storage tank of liquid reducing agent, and is characterized in that empty is judged by utilizing the liquid-level based on the liquid-level sensor in addition to the concentration based on the concentration sensor (step 3 and step 5). Even if a bubble is adhering to the concentration sensor and an erroneous signal indicative of empty is output although the residual quantity of liquid reducing agent is sufficient, the liquid-level sensor does not output a signal indicative of empty. Consequently, erroneous judgment is prevented and accurate judgment can be made as compared to heretofore.

Abstract: A urea sensor includes a detecting portion which, in use, is immersed in a liquid accommodated in a urea solution tank for detecting the thermal conductivity of the liquid to detect whether the liquid accommodated in the urea solution tank is an aqueous urea solution; and an enclosing member enclosing a periphery of the detecting portion and including one or more vents penetrating the enclosing member. At least one of the vents is a lower vent being of a configuration and size such that a first hypothetical circle having a diameter of not less than 3.5 mm can be wholly contained within the lower vent. At least a portion of the lower vent is positioned below the detecting portion when the urea sensor is positioned for installation in the urea solution tank.

Abstract: A sensor for detecting a state of liquid contained in a container comprising an outer tubular electrode made of an electrically conductive material, an inner electrode made of an electrically conductive material and disposed concentrically within the outer tubular electrode, a base end support member supporting base end portions of the outer tubular electrode and the inner electrode in a way as to provide insulation therebetween, and a leading end support member elastically supporting a leading end portion of the inner electrode on an inside of a leading end portion of the outer tubular electrode.

Abstract: A liquid state detecting apparatus including a detecting element having a heating resistor which generates heat when energized and being disposed in a liquid container for containing a liquid, the apparatus calculating a first difference between a first corresponding value corresponding to a first resistance of the heating resistor acquired after energization of the heating resistor is started and a second corresponding value corresponding to a second resistance of the heating resistor acquired after the heating resistor is energized for a predetermined detection time and obtaining a first concentration of a particular component included in the liquid, the first concentration being associated with the first difference, the apparatus including: an abnormality determination unit, a determination concentration acquiring unit, a concentration difference calculation unit, and a static state determination unit, all as defined herein.

Abstract: A liquid state detecting sensor for detecting a state of a liquid including a liquid concentration detecting element, a holder member, and an enclosing member as defined herein, wherein the holder member has a configuration in which respective portions of a lower end surface facing the enclosed region are located higher than or at a same height as a lowest hole periphery at the rim of the element holding hole from which the detecting element protrudes, and at least one of circulation holes formed in the enclosing member is a bubble-discharging hole which has an upper end located higher than the lowest hole periphery and a lower end located lower than a surface peripheral edge of the lower end surface.

Abstract: A liquid-condition detection sensor (1) including a sensor element (51), at least a portion of which contacts a urea aqueous solution; connection terminals (52) fixedly attached to the sensor element (51); connection cables (53) which electrically communicate with the concentration sensor element (51) via the connection terminals (52); an inner tube (42) which holds the concentration sensor element (51) at a distal end portion (421) by use of a holder member (55) and surrounds a portion of the connection cables (53) and the entire connection terminals (52); and a separator formed from a material having rubberlike elasticity (54) including a terminal-inner-tube-insulating portion (542) which intervenes between the connection terminals (52) and the inner tube (42) to thereby insulate the connection terminals (52) and the inner rube (42) from one another.

Abstract: A liquid state detecting sensor is provided in which a level detecting unit for detecting the level of a liquid and a concentration detecting unit for detecting the concentration of a particular component contained in the liquid are integrated. In a liquid state detecting sensor 100 capable of measuring the level and a urea concentration of a urea aqueous solution, a level detecting unit 70 and a liquid property detecting unit 30 are connected in an insulated state. An outer cylinder electrode 10 and an inner electrode 20 for forming the level detecting unit 70 form a capacitor, and level detection is performed on the basis of the electrostatic capacity which changes in response to the level of the urea aqueous solution which is present therebetween. A holder 120 for holding a ceramic heater 110 is fitted to a leading end portion 21 of the inner electrode 20, and the holder 120 is supported inside a leading end portion 11 of the outer cylinder electrode 10 by a rubber bushing 80.

Abstract: A sensor for detecting a state of liquid contained in a container comprising an outer tubular electrode made of an electrically conductive material, an inner electrode made of an electrically conductive material and disposed concentrically within the outer tubular electrode, a base end support member supporting base end portions of the outer tubular electrode and the inner electrode in a way as to provide insulation therebetween, and a leading end support member elastically supporting a leading end portion of the inner electrode on an inside of a leading end portion of the outer tubular electrode.

Abstract: A liquid state detecting apparatus including a detecting element which outputs a signal associated with a concentration of a particular component of a liquid contained in a liquid container; an abnormality determination unit which determines whether or not the liquid is in a particular abnormal state based on the output signal of the detecting element, a level detecting part which outputs a signal according to a level of the liquid contained in the liquid container; and a static state determination unit which determines whether or not the liquid in the liquid container is in a static state based on the output signal from the level detecting part, wherein the determination made by the static state determination unit is reflected in the determination made by the abnormality determination unit.

Abstract: An apparatus for distinguishing a liquid reducing agent which judges empty with a higher precision than heretofore is provided. The apparatus for distinguishing a liquid reducing agent is provided with a concentration sensor and a liquid-level sensor in a storage tank of liquid reducing agent, and is characterized in that empty is judged by utilizing the liquid-level based on the liquid-level sensor in addition to the concentration based on the concentration sensor (step 3 and step 5). Even if a bubble is adhering to the concentration sensor and an erroneous signal indicative of empty is output although the residual quantity of liquid reducing agent is sufficient, the liquid-level sensor does not output a signal indicative of empty. Consequently, erroneous judgment is prevented and accurate judgment can be made as compared to heretofore.

Abstract: A liquid state detecting sensor includes: a state detecting element including a heating resistor; an energization unit; a first output acquiring unit; a reference acquiring unit; a first calculating unit; a state detecting unit; a second output acquiring unit; a second calculating unit; an excess-temperature-rise determining unit; and an energization terminating unit. The energization termination unit terminates energizing of the heating resistor by the energization unit before the end of a detection time period in response to a determination by the excessive-temperature-rise determining unit that an excessive temperature rise has occurred in the state detecting element.

Abstract: A liquid state detection sensor in which temperature information of a urea aqueous solution is obtained on the basis of a voltage value acquired after the start of energization of a heating resistor corresponding to a resistance value of the heating resistor (S1-S6). Damage to the heating resistor is prevented by suspending the energization if the thus-obtained temperature is lower than or equal to the freezing point (S7: yes and S8). If the temperature is higher than the freezing point (S7: no), a voltage value corresponding to a resistance of the heating resistor after a lapse of 700 ms (S10 and S11) and a urea concentration of the urea aqueous solution are determined from a difference ?V from the previously acquired voltage value. A more accurate urea concentration can be detected by making a correction using the previously obtained temperature information of the urea aqueous solution (S13-S18).

Abstract: The present invention provides a liquid state detecting sensor that is free from a problem of increase in the number of parts and a problem in assembly and furthermore capable of, in support of electrodes, absorbing an error and supporting both electrodes, even in case an inner electrode has at a surface an insulation layer, without causing any damage to the layer. The liquid state detecting sensor includes an outer tubular electrode 10 shaped tubular and formed from a conductor, an inner electrode 20 in the form of a shaft and disposed along an axial direction G and within the outer tubular electrode, and a base end support member 40 that supports, at base end sides of the both electrodes 10 and 20, the both electrodes 10 and 20 while holding the electrodes insulated from each other, and detects a level of liquid within a tank 1, etc.

Abstract: A liquid state detecting sensor is provided in which a level detecting unit for detecting the level of a liquid and a concentration detecting unit for detecting the concentration of a particular component contained in the liquid are integrated. In a liquid state detecting sensor 100 capable of measuring the level and a urea concentration of a urea aqueous solution, a level detecting unit 70 and a liquid property detecting unit 30 are connected in an insulated state. An outer cylinder electrode 10 and an inner electrode 20 for forming the level detecting unit 70 form a capacitor, and level detection is performed on the basis of the electrostatic capacity which changes in response to the level of the urea aqueous solution which is present therebetween. A holder 120 for holding a ceramic heater 110 is fitted to a leading end portion 21 of the inner electrode 20, and the holder 120 is supported inside a leading end portion 11 of the outer cylinder electrode 10 by a rubber bushing 80.

Abstract: A urea sensor includes a detecting portion which, in use, is immersed in a liquid accommodated in a urea solution tank for detecting the thermal conductivity of the liquid to detect whether the liquid accommodated in the urea solution tank is an aqueous urea solution; and an enclosing member enclosing a periphery of the detecting portion and including one or more vents penetrating the enclosing member. At least one of the vents is a lower vent being of a configuration and size such that a first hypothetical circle having a diameter of not less than 3.5 mm can be wholly contained within the lower vent. At least a portion of the lower vent is positioned below the detecting portion when the urea sensor is positioned for installation in the urea solution tank.

Abstract: A liquid state detecting sensor includes: a state detecting element including a heating resistor; an energization unit; a first output acquiring unit; a reference acquiring unit; a first calculating unit; a state detecting unit; a second output acquiring unit; a second calculating unit; an excess-temperature-rise determining unit; and an energization terminating unit. The energization termination unit terminates energizing of the heating resistor by the energization unit before the end of a detection time period in response to a determination by the excessive-temperature-rise determining unit that an excessive temperature rise has occurred in the state detecting element.

Abstract: An electrostatic capacity type liquid state detecting sensor includes an outer tubular electrode, and an inner electrode disposed within the outer tubular electrode and having an insulation layer at an outer surface portion to be brought into contact with liquid contained in a container for detection of a state of the liquid, wherein the thickness of the insulation layer is less than 500 ?m and not less than 100 ?m.

Abstract: A liquid state detecting sensor for detecting a state of a liquid including a liquid concentration detecting element, a holder member, and an enclosing member as defined herein, wherein the holder member has a configuration in which respective portions of a lower end surface facing the enclosed region are located higher than or at a same height as a lowest hole periphery at the rim of the element holding hole from which the detecting element protrudes, and at least one of circulation holes formed in the enclosing member is a bubble-discharging hole which has an upper end located higher than the lowest hole periphery and a lower end located lower than a surface peripheral edge of the lower end surface.

Abstract: The present invention provides a capacitive liquid state sensor configured to release a pressure in an intervening gap by providing slits to an outer tubular electrode while inhibiting decrease in strength caused by forming of the slits. The outer tubular electrode 20 disposed with a predetermined distance from an inner electrode 20 is formed with a plurality of slits 14, 15 and 16 along a generator (indicated by one-dot chain line A) extending from a front end portion 11 to a rear end portion 12. Between the slits 14, 15 and 16 are positioned intermediate no-slit formed areas 17 and 18. Circulation of liquid between the inside and the outside of the outer tubular electrode 10 and in the axial direction of the same electrode 10 is attained through the slits 14, 15 and 16, so that a pressure accompanied by volumetric expansion of liquid at the time of freezing and existing in the intervening space can be released to the outside.

Abstract: A liquid-condition detection sensor (1) includes a concentration sensor element (260) for detecting the condition of liquid to be measured; a wiring board (40) including a driving control circuit (41) disposed above the concentration sensor element (260); a cable (50) mechanically connected to the wiring board (40), extending downward from the wiring board (40), and establishing an electrical connection between the driving control circuit (41) and the concentration sensor element (260); an inner tube (221) surrounding at least a portion of a cable (50) in a loose condition; and a fixing holder section (94) fixedly holding a portion (51) of the cable (50) located between the wiring board (40) and the concentration sensor element (260).