The present invention makes it possible for an automated analyzer including two or more types of photometers to obtain suitable output of the measurement results of the plurality of photometers and suitable data alarm output even if there is an abnormality, or the like, at the time of measurement. This automated analyzer includes, for example, two types of photometers having different quantitative ranges and an analysis control unit for controlling analysis that includes measurement of a given sample using the two types of photometers. If two types of data alarms corresponding to abnormalities, or the like, during measurement have been added to the two types of measurement results from the two types of photometers, the analysis control unit selects measurement result and data alarm output corresponding to the combination of the two types of data alarms and outputs the same to a user as analysis results.

A gas sensor includes a measurement chamber, a reference gas chamber, a first cell, and a second cell. The first cell includes a first electrode in the measurement chamber and a second electrode in the reference gas chamber. The second cell includes a third electrode in the measurement chamber and a fourth electrode in the reference gas chamber. A gas sensor detects a first current that flows between the first electrode and the second electrode, detects a second current that flows between the third electrode and the fourth electrode, calculates a concentration of a specific gas component based on a detected value of the second current, estimates a change amount of oxygen concentration in the reference gas chamber based on a detected value of the first current, and corrects the detected value of the second current based on an estimated value of the change amount of the oxygen concentration.

A method and a device for performing diagnostics on an exhaust gas sensor includes a series circuit of a Nernst cell and a first other cell. The exhaust gas sensor has a first, a second, and a third connection where a voltage drop can be measured between the first connection and the second connection by the Nernst cell and a voltage drop between the second connection and the third connection can be measured by the first other cell. The diagnostic method has steps for feeding a direct or alternating current into the first, second, and third connections; for directly or indirectly sensing an electrical voltage potential at at least one of the first, second, and third connections; and for evaluating the voltage potential sensed to diagnose a short circuit or an open circuit in the Nernst cell and/or in the first other cell.

An oxygen concentration meter includes a zirconia sensor, a resistor, a constant-current circuit, a resistance detection section, and an oxygen concentration detection section. The resistor is connected in parallel to the zirconia sensor. The constant-current circuit is connected in parallel to the zirconia sensor and the resistor, and supplies an electric current. The resistance detection section detects the resistance of the zirconia sensor on the basis of the voltage of the zirconia sensor in accordance with the supplied electric current. The oxygen concentration detection section detects the oxygen concentration of gas to be measured that is supplied to the zirconia sensor, on the basis of the voltage of the zirconia sensor resulting from an oxygen concentration difference between the gas to be measured and reference gas.

A sensor system (1, 1S) including a current DA converter (42) outputting a control current (Ip) of a sensor element (3S), a control unit (4C) generating a control current instruction value (Ipcmd) corresponding to magnitude of the control current and inputting this instruction value to the current DAC, an instruction value sequence generating unit (47) generating, instead of the control current instruction value, an inspection instruction value sequence (RChcmd) in which predetermined inspection current instruction values (Chcmd) inputted to the current DAC are arranged in order and by which failure of the current DAC can be detected, an inspection current detection unit (71) detecting an inspection current value (Ichv) of an inspection current (Ich) outputted from the current DAC, and a failure detection unit (8) detecting failure of the current DAC from an inspection current value sequence (RIchv) in which the inspection current values are arranged in order of detection.

The invention provides a gas detection system and a method with eliminating influence of ambient temperature and humidity change, the gas detection system comprises a bare sensor, a reference sensor and a calculation module; the bare sensor is used to detect a target gas in an ambient gas to obtain a first feedback signal; the reference sensor is used to selectively isolate the target gas in the ambient gas to produce a zero gas and to detect the zero gas to obtain a second feedback signal, the calculation module is used to calculate a difference between the first feedback signal and the second feedback signal to obtain a third feedback signal, and to obtain a target gas concentration by calculating the third feedback signal according to a calibration formula. The invention improves the measurement accuracy to the target gas concentration, which are efficient and reliable and have good technical effects.

The control section of a control apparatus executes a first control for operating a voltage application section such as to cause a current to flow in a first direction through a gas sensor in a first period, and a second control for operating the voltage application section such as to cause a current to flow in a second direction, opposite to the first direction, through the gas sensor in a second period. The control apparatus changes the length of at least one of the first period and the second period based on a comparison between a first measurement value, which is the absolute value of a value measured by a sweep measurement section during execution of the first control, and a second measurement value, which is the absolute value of a value measured by the sweep measurement section during execution of the second control.

A sensor element used to detect, using a limiting current method, the specific gas concentration in a rich-atmosphere measurement-object gas. The sensor element includes a layered body in which a measurement-object gas distribution portion is provided, an adjustment pump cell that has an adjustment pump electrode arranged in an oxygen concentration adjustment space in the measurement-object gas distribution portion. The adjustment pump electrode contains Pt and Au, and a Au/Pt ratio (=the area of a portion where Au is exposed/the area of a portion where Pt is exposed) measured using X-ray photoelectron spectroscopy (XPS) is greater than or equal to 0.3 but not greater than 0.63.

A gas sensor control apparatus (300) including a control section (61) which executes a first receiving process (STEP 1) for receiving a first detection result output from a mixed-potential-type ammonia detection section (42) for detecting ammonia contained in a gas under measurement and corresponding to the concentration of ammonia, a second receiving process (STEP 1) for receiving a second detection result output from an oxygen detection section (2) for detecting oxygen contained in the gas under measurement and corresponding to the concentration of oxygen, a first concentration calculation process (STEP 3) for calculating a first ammonia concentration of the gas under measurement based on the first detection result and the second detection result, and a pressure correction process (STEP 6) for correcting the first ammonia concentration based on pressure information obtained from an external device (220), thereby obtaining a second ammonia concentration of the gas under measurement.

An oxygen concentration meter includes a zirconia sensor, a resistor, a constant-current circuit, a resistance detection section, and an oxygen concentration detection section. The resistor is connected in parallel to the zirconia sensor. The constant-current circuit is connected in parallel to the zirconia sensor and the resistor, and supplies an electric current. The resistance detection section detects the resistance of the zirconia sensor on the basis of the voltage of the zirconia sensor in accordance with the supplied electric current. The oxygen concentration detection section detects the oxygen concentration of gas to be measured that is supplied to the zirconia sensor, on the basis of the voltage of the zirconia sensor resulting from an oxygen concentration difference between the gas to be measured and reference gas.