Abstract: An online calibration system for an electrochemical sensor. The calibration system comprises a calibration electrode coupled with a redox species, where the redox species is configured to control a pH of a reference solution local to the calibration electrode, such that when a voltammetric signal is applied to the calibration electrode the output generated from the calibration system is determined by the local environment pH. The output signal from the calibration system is used to calibrate a reference potential generated by a reference system of the electrochemical sensor to correct for drift in the reference potential when the electrochemical sensor is being used. The calibration electrode may be disposed in a reference cell of the electrochemical sensor.

Abstract: Disclosed herein are systems and methods for a continuous analyte sensor, such as a continuous glucose sensor. One such system utilizes first and second working electrodes to measure additional analyte or non-analyte related signal. Such measurements may provide a background and/or sensitivity measurement(s) for use in processing sensor data and may be used to trigger events such as digital filtering of data or suspending display of data.

Abstract: A method and apparatus extend the measurement life of a working electrode in a three-electrode amperometric sensor by applying an activation sequence of voltages and a measurement sequence of voltages to the input of a potentiostat. The activation sequence includes multiple cycles wherein each cycle includes a low (more negative) voltage and a high (more positive) voltage (e.g., 0 volts) with reference to a signal ground reference. In one mode, the measurement sequence includes multiple cycles of three voltage pulses, wherein each cycle includes a measurement voltage pulse followed by a high (more positive) pulse, followed by a low (more negative) pulse. The cycles are repeated N times. In a second mode, the measurement sequence comprises a fixed measurement voltage having selectable duration.

Abstract: An apparatus for measuring a concentration of an analyte in a bio-sample using an electrochemical bio-sensor, includes a connector with a sample cell in which an oxidation/reduction enzyme and an electron transfer mediator are fixed and a working electrode and an counter electrode are provided; a digital-to-analog converter circuit configured to apply a constant DC voltage to start the oxidation/reduction reaction of the analyte, proceed with an electron transfer reaction, and apply a ?-step ladder-type perturbation potential for fluctuating a potential of the sample cell after applying the constant DC voltage; and a microcontroller configured to control the digital-to-analog converter circuit and directly obtain a concentration value of the analyte from a calibration equation using the ?-step ladder-type perturbation potential.

Abstract: The present invention involves a rotary peristaltic pump and associated method employing the relaxation of pressure on flexible tubing between the rotor and stator of the pump to restore the rotor to a start angle while a valve on the output of the pump is closed to avoid progress of fluid through the system. Three different implementations of the pump and method are presented including reciprocating the stator, reciprocating the rotor, and retracting the idler rollers of the rotor into the rotor to relieve the pressure on the flexible tubing. A controller ensures the appropriate switching and timing of the valve and rotor of the pump. The pump and associated method are directed to the precision dispensing of pharmaceutical fluids into containers, including containers held in container nests.

Abstract: A method for sensing an analyte utilizing a sensor having a working electrode, the method includes providing the working electrode with an analyte-specific enzyme and a redox mediator, providing the working electrode to the analyte, accumulating charge derived from the analyte reacting with the analyte-specific enzyme and the redox mediator for a set period of time, connecting the working electrode to circuit after the set period of time, and measuring the signal from the accumulated charge.

Abstract: A method for cancer diagnosis is disclosed. The method includes forming a plurality of cultured cells on an electrochemical biosensor placing the electrochemical biosensor in a medium solution comprising a cell culture solution of a plurality of biological cells, measuring a first electrochemical response from the electrochemical biosensor with the plurality of cultured cells, forming a plurality of stimulated cells on the electrochemical biosensor by ultrasonically stimulating of the plurality of cultured cells, measuring a second electrochemical response from the electrochemical biosensor with the plurality of stimulated cells, and detecting presence of cancer cells responsive to a difference between the first electrochemical response and the second electrochemical response being less than a threshold.

Abstract: The present invention relates to an electrochemical advanced oxidation process combined with a membrane in which electrode reactions and membrane filtration occur simultaneously, a water treatment device based on the electrochemical advanced oxidation process, and a water treatment system using the water treatment device. The electrochemical advanced oxidation process includes: providing a membrane electro-oxidation tank where electrodes are combined with a membrane; accommodating wastewater containing pollutants in the membrane electro-oxidation tank; and supplying power to the electrodes to decompose the pollutants and simultaneously separating particles through the membrane (water treatment). The electrodes are arranged downstream of the membrane. Gases released from the electrodes induce a vertical flow of the fluid to improve the contact efficiency between a reactive solution and the electrodes and remove the pollutants attached to the surface of the membrane.

Abstract: A measurement device including: an ion-sensitive element; a reference electrode disposed in a state in which a measurement subject is interposed between the reference electrode and the ion-sensitive element; and a controller configured to: establish a first state at a predetermined interval, the first state being a state in which a current flows at the ion-sensitive element, and establish a second state within each period after the first state has been established and before the first state is next established, the second state being a state in which a potential difference between the ion-sensitive element and the reference electrode is greater than a potential difference between the ion-sensitive element and the reference electrode in the first state.

Abstract: The present invention involves a rotary peristaltic pump and associated method employing the relaxation of pressure on flexible tubing between the rotor and stator of the pump to restore the rotor to a start angle while a valve on the output of the pump is closed to avoid progress of fluid through the system. Three different implementations of the pump and method are presented including reciprocating the stator, reciprocating the rotor, and retracting the idler rollers of the rotor into the rotor to relieve the pressure on the flexible tubing. A controller ensures the appropriate switching and timing of the valve and rotor of the pump. The pump and associated method are directed to the precision dispensing of pharmaceutical fluids into containers, including containers held in container nests.

Abstract: A method of recovering a target from a sample is provided. The method of recovering the target follows different steps. The steps include providing a binding element, wherein the binding elements are immobilized on a solid support, adding the sample comprising the target to the binding element to form a binding element-target complex; washing the binding element-target complex; and eluting the target from the binding element-target complex. The system for reversible detection of target in a range from 2 to 1,000,000 bind/release cycles is also provided.

Abstract: A biosensor system determines analyte concentration from analytic and/or secondary output signals. The biosensor system adjusts a correlation for determining analyte concentrations from output signals with one or more index functions extracted from the output signals. The index functions determine at least one slope deviation or normalized slope deviation from one or more error parameters. The slope-adjusted correlation between analyte concentrations and output signals may be used to determine analyte concentrations having improved accuracy and/or precision from output signals including components attributable to bias.

Abstract: A sensor system, device, and methods for determining the concentration of an analyte in a sample is described. Input signals including multiple duty cycles of sequential excitation pulses and relaxations are input to the sample. One or more signals output from the sample within 300 ms of the input of an excitation pulse may be correlated with the analyte concentration of the sample to improve the accuracy and/or precision of the analysis. Determining the analyte concentration of the sample from these rapidly measured output values may reduce analysis errors arising from the hematocrit effect, mediator background, and other error sources.

Abstract: An analyte concentration can be measured at an electrochemical detector using a waveform that includes a reductive voltage. The waveform may include three or four different voltages, in which at least one of the voltage values is reductive. One or more current or charge values can be measured during at least part of a reductive voltage portion of the waveform. The analyte concentration can be calculated based on the measured one or more current or charge values.

Abstract: A system for monitoring doses from an ionizing radiation source to a treatment region of a patient and immobilizing a body cavity relative to the treatment region, is provided. The system includes a probe body for insertion into the body cavity. The probe body separates the body cavity from the treatment region to reduce exposure to doses from the ionizing radiation source. Radiation detectors are disposed along the probe body to measure at least one dose. A slot disposed adjacent the radiation detectors receives a dosimetry film that, upon exposure to the one or more doses from the ionizing radiation source, indicates a quantification of the doses. A coupling is in fluid communication with a removable sheath having coupled thereto a vacuum or a pump to remove fluid or gas from the body cavity and ensure inner wall of the body cavity is in contact with the sheath.

Abstract: Techniques for improving noise performance while processing signals received from an electrochemical sensor are provided. In an example, an interface circuit can include a first amplifier configured to provide a voltage to a counter electrode of an electrochemical sensor, a second amplifier configured to receive sensor information from a working electrode of the electrochemical sensor and to provide concentration information using the sensor information. In certain examples, an input of the first amplifier can be directly coupled to an input of the second amplifier to attenuate noise, of either the first amplifier or the second amplifier, within the concentration information provided by the second amplifier.

Abstract: A method for measuring a concentration of an analyte in a bio-sample using an electrochemical bio-sensor according to an exemplary embodiment of the present invention is characterized by a step of obtaining predetermined features from induced currents obtained by applying a DC voltage according to chronoamperometry in which, after a whole blood sample is injected to the electrochemical bio-sensor, a concentration of an analyte is obtained from an induced current obtained by applying a DC voltage for a certain time and from all induced currents obtained by further applying several step-ladder perturbation potentials for a short time subsequent to the DC voltage for the certain time, and is also characterized by minimization of a measurement error caused by a hindering material by forming a calibration equation by combining the at least one feature in a function and optimizing various conditions of the bio-sample through DeletedTextsmultivariable analysis.

Abstract: A biosensor system determines analyte concentration from an output signal generated from a light-identifiable species or a redox reaction of the analyte. The biosensor system adjusts a correlation for determining analyte concentrations from output signals or determined analyte concentrations with one or more complex index function extracted from the output signals or from other sources. The complex index functions determine at least one slope deviation value, ?S, or normalized slope deviation from one or more error parameters. The slope-adjusted correlation between analyte concentrations and output signals may be used to determine analyte concentrations having improved accuracy and/or precision from output signals including components attributable to bias.

Abstract: Control of humidity in chemical reactors, and associated systems and methods, are generally described. In certain embodiments, the humidity within gas transport conduits and chambers can be controlled to inhibit unwanted condensation within gas transport pathways. By inhibiting condensation within gas transport pathways, clogging of such pathways can be limited (or eliminated) such that transport of gas can be more easily and controllably achieved. In addition, strategies for purging condensed liquid from chemical reactor systems are also described.

Abstract: A sulfur oxide detection system includes an element part which includes a sensor cell and a diffusion regulating layer. The sensor cell includes a solid electrolyte layer, a first electrode arranged, and a second electrode. The sulfur oxide detection system also includes a voltage application circuit configured to apply a voltage to the sensor cell so that a potential of the second electrode becomes higher than a potential of the first electrode, and a current detection circuit configured to detect a current flowing between the first electrode and the second electrode. The sulfur oxide detection system further includes a controller coupled with the voltage application circuit and the current detection circuit, and configured to estimate a sulfur oxide concentration in a gas to which the first electrode is exposed by way of the diffusion layer.

Abstract: Embodiments provide silver detection systems and methods for detecting the presence of silver ions in one or more samples. In a detection method, a sample and TPEA2 molecules are introduced into a channel. A first potential difference is applied across the length of the channel in a first direction, and a first electrical property value is detected. Subsequently, a second potential difference is applied across the length of the channel in a second opposite direction, and a second electrical property value is detected. Presence or absence of silver ions in the channel is determined based on a comparison between the first and second electrical property values.

Abstract: A carbon quantifying cell configured to receive a fluid is provided, including two or more electrodes positioned at least partially in the fluid, and meter electronics configured to place an electrical oxidization, polarization, and/or adsorption program across the two or more electrodes and at least partially oxidize carbon materials in the fluid, apply an AC voltage of a predetermined amplitude across the two or more electrodes, measuring the resulting AC current across the two or more electrodes, wherein a ratio of amplitudes and a phase angle difference provides information for calculating a fluid impedance, receive an electrical response of the fluid to the electrical oxidization, polarization, and/or adsorption program, quantify the carbon materials in the fluid using the electrical response, and detect interfering materials in the fluid using the fluid impedance.

Abstract: A pH sensor contains a potentiometric sensing electrode made of palladium. An optional metal oxide layer may be coated on the palladium electrode to enhance sensitivity. The pH sensor has high sensitivity, a shorter response time, and good reversibility and stability.

Abstract: A flow cell for electrochemical measurement which introduces a sample solution, applies a voltage between a working electrode and a counter electrode to analyze the sample solution electrochemically, discharges the sample solution, and performs the electrochemical measurement continuously. The flow cell includes a unit which measures a value of a current flowing between electrodes at the time of applying a voltage, a unit which records the measured current value, a unit which compares the recorded current value with a current value set separately as a determination standard, and a unit which determines whether the current value measured at a cycle of a determination target and the recorded current value is normal by the comparison.

Abstract: A biosensor system determines analyte concentration from analytic and/or secondary output signals. The biosensor system adjusts a correlation for determining analyte concentrations from output signals with one or more index functions extracted from the output signals. The index functions determine at least one slope deviation or normalized slope deviation from one or more error parameters. The slope-adjusted correlation between analyte concentrations and output signals may be used to determine analyte concentrations having improved accuracy and/or precision from output signals including components attributable to bias.

Abstract: A temperature sensor has a thermosensitive element that detects temperature, a pair of element electrode wires electrically connected to the thermosensitive element, and a glass sealing body that has a sealing portion covering the thermosensitive element and a part of the element electrode wires. Further, the temperature sensor has a tablet that has an interface and a pair of insertion holes into which the element electrode wires are inserted, the tablet being joined to the glass sealing body through the interface. Further, the temperature sensor has a low Young's modulus layer provided in the glass sealing body, made of a material having lower low Young's modulus than that of a material forming the sealing portion, and at least partially connecting the sealing portion and the interface of the tablet.

Abstract: The present invention relates to a water drain system of an oil reserve tank, which comprises: an oil reserve tank; an oil and water separator for separating the drained water coming from the oil reserve tank; a drain pipe extended from the oil reserve tank to the oil and water separator, the drain pipe having a vertical part to form a step; and a water detection sensor installed in the vertical part.

Abstract: An analysis chip device according to an exemplary embodiment of the present invention includes a placing board (17) on which a microchip (14) is placed, and a coupling (20) attached to a cover (11) of the microchip (14). The coupling (20) includes a linear electrode (25), a sleeve (22) including an attach part (28) that is attached to the cover (11) and an air core part (23) in which the electrode (25) is provided, the sleeve (22) having a side surface in which an inlet port (26) is provided, the inlet port (26) communicating with the air core part (23); and a holder (21) including a pipe connection part (27) to which a pipe (32) is connected, the pipe (32) supplying gas to the inlet port (26), the holder (21) holding the sleeve (22) so as to surround the inlet port (26).

Abstract: A method of testing a system, which has at least one electrochemical sensor for detecting an analyte gas within a housing of the system, and the housing has an inlet, includes exhaling in the vicinity of the inlet of the housing of the system and measuring a response to exhaled breath to test one or more transport paths of the system. Measuring the response to exhaled breath may, for example, include measuring the response of a sensor within the housing of the system that is responsive to the presence of exhaled breath. The sensor responsive to the presence of exhaled breath may, for example, include an electrochemically active electrode responsive to a gas within exhaled breath. The electrochemically active electrode may, for example, be responsive to carbon dioxide or to oxygen.

Abstract: Electrodes are positioned substantially in contact with at least one surface of a solid to generate or absorb alkali metals when a voltage is applied between the electrodes.

Abstract: Provided herein are methods, apparatuses, and systems for enhancing the detection of reactive gases, such as ethylene gas, that are present at low concentrations in air samples. The methods and systems enhance the selectivity, sensitivity, and accuracy of electrochemical cells by removing interfering gases from the air samples. Some systems include an ethylene sensor that includes an electrochemical cell and a polar solvent gas trap pre-filter, wherein the gas trap is positioned upstream of the electrochemical cell. Some methods are methods of measuring an ethylene level in an air sample, and include passing the air sample by through a polar solvent gas trap, and measuring the ethylene level in the air sample with an electrochemical cell.

Abstract: A biosensor with an underfill recognition system assesses whether to analyze a sample for one or more analytes in response to the volume of the sample. The underfill recognition system applies polling and test excitation signals to the sample. The polling signals generate one or more polling output signals, which maybe used to detect when a sample is present and to determine whether the sample has sufficient volume for analysis. The test excitation signal generates one or more test output signals, which may be used to determine one or more analyte concentrations in the sample.

Abstract: Disclosed is a method and apparatus for detecting the concentration of a lipophilic analyte of interest in a complex sample matrix. The method comprises extracting the analyte of interest from said sample into an organic solvent comprising a dissolved electrolyte; providing a free radical species, preferably a free oxygen radical species, in said organic solvent; reacting the analyte of interest with said free radical species; and performing a measurement to detect the concentration of the free radical-reacted analyte reaction product.

Abstract: An apparatus for automatically conditioning a patch plate and a plenum of an electrophysiology measurement system is provided. An arm is linearly movable between a non-operative position and an operative position. An end effector mounted to one side of the arm is configured to condition the patch plate. Another end effector mounted to an opposite side of the arm is configured to condition the plenum. A linear actuator is coupled to the arm and is configured to drive movement of the arm between the operative position and the non-operative position. When the arm is positioned in the operative position, the arm is situated between the patch plate and the plenum.

Abstract: A remotely readable hydrogen detector is in the form of a tag or card that can be worn on clothing or mounted on a variety of surfaces and can be monitored from a distance for the presence of hydrogen gas. It includes a hydrogen sensor device, which changes in electrical resistivity in response to being exposed to hydrogen gas, that is incorporated into an electric detector circuit, which detects changes in resistivity of the sensor device, and, when such change in resistivity indicates the presence of some predetermined concentration of hydrogen gas, the electric circuit outputs a signal or state that indicates the presence of hydrogen to a transceiver circuit, which can transmit that information to a remote receiver or interrogator/reader via an antenna in the sensor device.

Abstract: The evaporation of the stripping liquid 6 changes the concentration of the standard electrolyte. This causes the quantification accuracy of the chemical substance to be lowered. In order to solve the above problem, this invention provides a method for quantifying a chemical substance contained in a sample solution, characterized by the following stripping gel. The stripping gel covers the stripping electrode, and contains a standard electrolyte and an ionic liquid; however, the stripping gel contains no water. Furthermore, the ionic liquid is hydrophobic and nonvolatile, and the standard electrolyte is consisted of the anion and a metallic ion.

Abstract: A method and apparatus measures the presence of total residual oxidant species in aqueous environments. More specifically, the apparatus is operable to measure hypohalites (e.g., hypochlorite and hypobromite) in water containing halide salts using electrochemistry. The apparatus can be a sensor having four electrodes—a reference electrode, a working electrode, and two auxiliary electrodes. The fourth electrode, i.e., the second auxiliary electrode, can be used to generate ionized water near and in contact with the working electrode. The ionized water can clean the working electrode to minimize effects due to scaling or biofilm formation. As such, the working electrode does not need the capability to clean itself. Thus, other elements, originally believed to be unsuitable for use in saline aqueous environments, can be used for the electrodes, for example, gold.

Abstract: The purpose of the invention is to provide a method for quantifying a chemical substance with high accuracy using substitutional stripping voltammetry and a sensor chip used therefor. A sensor chip comprising a stripping electrode which is covered with stripping gel and a method utilizing the sensor chip. A reaction represented by the following formula (III) occurs at the stripping electrode. [Chem.

Abstract: Provided are a method for quantifying a chemical substance with high accuracy by substitutional stripping voltammetry, and a sensor chip used therefor. A method for quantifying a chemical substance in a sample solution, comprising the following steps: (a) preparing a sensor chip having a stripping gel covered with a protection gel, (b) supplying the sample solution to the surface of the sensor chip to cover the surface with the solution, (c) applying a potential to the first working electrode with potentiostat, and connecting the second working electrode to the stripping electrode to generate reactions on the electrodes, (d) applying a potential to the stripping electrode in a condition where no potential is applied to either the first or the second working electrode to measure a current through the stripping electrode, and (e) calculating, on the basis of the current, the concentration of the oxidation-reduction substance to quantify the chemical substance.

Abstract: The present invention pertains to a means of combining and configuring specific hydrophilic and dielectric materials in such a way as to allow an antimony/reference electrode pH sensor to be packaged and stored dry yet become fully hydrated to an activated state after exposure to aqueous liquids. The sensor is packaged and stored dry to maintain component stability and minimize component degradation. When the user removes the sensor from the package and the sensor tip is submerged in a hydration (ion conduction) media or solution, the hydrophilic coating along with the impregnated reference wick, absorb the fluid to create an electrolytic gel inside the reference wick, which activates the pH sensor.

Abstract: A medical device includes a connector which contacts a sensor to electrically connect the sensor with a measurement circuit in a medical device, a contact terminal which constitutes the connector, and a slide pin which ejects the sensor out of the medical device. The slide pin performs the operation of pushing up the contact terminal contacting the sensor as well as the operation of pushing the sensor out of the medical device. Since the contact terminal is completely lifted up by the inclined surface of the upper end part of the slide pin before the sensor is discarded, there occurs no reaction due to rebound of the contact terminal which might occur at the moment when the contact terminal of the connector is separated from the sensor, and thereby the sensor can be discarded so as to fall freely.

Abstract: A hotplate chemical trace detector comprising a heatable conducting plate with a heater element having a predetermined temperature-power characteristic. A balancing circuit comprises an adjustable resistor for tuning the heater element to a predefined resistor value. A processor is provided for adjusting the adjustable resistor so as to provide a stabilized temperature in said heatable conducting plate and a detection circuit is provided for detecting a change of resistance in the heatable conducting plate in accordance with the presence of a chemical trace reacting in the presence of the conducting plate. According to the invention a test circuit is provided for measuring a dissipated power in the heater element and for calculating a real temperature from the dissipated power in the heater element based on the predetermined temperature-power characteristic.

Abstract: Methods for cleaning and regenerating a working electrode in an electrochemical cell; method for measuring the concentration of a metal in a liquid sample in an electrochemical cell having a working electrode, the method including a step for cleaning and/or regenerating the electrode; and an assembly having an ultrasonic device in sonic communication with an electrochemical cell.

Abstract: A regeneration apparatus for an electroless plating solution, which includes a sensor for measuring the formation rate of phosphorous acid formed in a plating tank in response to a plating treatment, a split device for taking out a plating solution in the plating tank to transfer the plating solution to a first processing tank, a sensor for measuring the concentration of the phosphorous acid contained in the plating solution taken out, an addition device for supplying calcium carbonate or calcium hydroxide, an amount of which is required for producing a calcium phosphite from the phosphorous acid contained in the plating solution, to the first processing tank, a separation device for separating and removing the calcium phosphite produced in the first processing tank from the plating solution, and a return pump for transferring the plating solution from which the calcium phosphite has been separated and removed to the plating tank.

Abstract: Methods are disclosed for reducing the shift in EMF bias in a magnesium ion selective electrode, comprising the step of: contacting the electrode with a composition comprising a polyoxyalkylene nonionic surfactant; wherein the polyoxyalkylene nonionic surfactant has an HLB greater than about 18. Additional aspects of the present invention are directed to methods, comprising the steps of: contacting a magnesium ion selective electrode with a composition comprising a polyoxyalkylene nonionic surfactant, wherein the polyoxyalkylene nonionic surfactant has an HLB greater than about 18; and measuring a biologically relevant level of a blood electrolyte in a blood composition with the electrode. In certain embodiments, the polyoxyalkylene nonionic surfactant is polyoxy ethylene (100) stearyl ether and the blood electrolyte is magnesium ion.

Abstract: A system and method are provided for cleaning combustion soot from an exhaust gas aftertreatment sensor. The system and method determine whether to conduct a sensor desoot event, and if it is determined that a sensor desoot event is to be conducted, the exhaust gas temperature is increased such that the temperature of the sensor correspondingly increases to or above a desoot temperature, the exhaust gas temperature is then controlled to maintain the temperature of the sensor at or above the desoot temperature for a predefined time period, and the exhaust gas temperature is then decreased after the temperature of the sensor has been at or above the desoot temperature for the predefined time period.

Abstract: A regeneration apparatus for an electroless plating solution includes a sensor for measuring the formation rate of phosphorous acid formed in a plating tank in response to a plating treatment, a split device for taking out a plating solution in the plating tank to transfer the plating solution to a first processing tank, a sensor for measuring the concentration of the phosphorous acid contained in the plating solution taken out, an addition device for supplying calcium carbonate or calcium hydroxide, an amount of which is required for producing a calcium phosphite from the phosphorous acid contained in the plating solution, to the first processing tank, a separation device for separating and removing the calcium phosphite produced in the first processing tank from the plating solution, and a return pump for transferring the plating solution from which the calcium phosphite has been separated and removed to the plating tank.

Abstract: Methods of estimating the temperature of a reaction site on a measurement strip in a blood glucose measuring devices are provided. In one embodiment, a method includes determining an activation initiation time, an activation duration time, a thermal magnitude and a temperature elevation for heat generating components within a device. The temperature elevation for each of the heat generating components is determined at least in part by an impulse response matrix [Xi], the activation initiation time, the activation duration time and the thermal magnitude for each of the heat generating components.

Abstract: A monitor is disclosed for monitoring an atmosphere for the presence of a target gas. The monitor includes an electrical gas sensor having a working (sensing) electrode and a counter electrode, an operational amplifier connected between the sensor electrodes, a detector, and a circuit. The sensor provides a current between the electrodes that is indicative of the amount of a target gas in the atmosphere. The operational amplifier generates an output signal according to the current flowing between the terminals where the output signal is indicative of the amount of target gas in the atmosphere. The detector detects when the current flowing between the sensor electrodes exceeds a predetermined threshold. The circuit restricts the potential difference between the sensor electrodes when the current between the terminals exceeds the predetermined threshold by supplying additional current or removing current from the working sensor electrode.

Abstract: A liquid property detecting device includes a switch portion switching an electrode to charge with a standard voltage generated by a generator, or discharge through a grounding. An operation signal output portion outputs an operation signal to the switch portion so as to switch in a predetermined switch period. A voltage of the electrode is output as a detection signal, when the standard voltage is applied to the electrode. A signal process portion calculates liquid property based on the detection signals. A gain of the signal process portion relative to the detection signal is increased, as the detection signal is decreased.