A method for determining a reference value of a presence of at least one substance (NO.sub.x) occurring in an exhaust gas stream of an internal combustion engine (101), wherein the at least one substance is subjected to exhaust treatment, the exhaust treatment being carried out in dependence on the reference value (Em.sub.ref; E.sub.mref,1; Em.sub.ref,2) When the internal combustion engine (101) is started: accumulating the occurrence (Em.sub.ACC,1; Em.sub.ACC,2) of the at least one substance (NO.sub.x) downstream from the exhaust treatment during a first period, and determining whether to redetermine the reference value (Em.sub.ref; Em.sub.ref,1; Em.sub.ref,2) based on the accumulated occurrence (Em.sub.ACC,1; Em.sub.ACC2) of the at least one substance (NO.sub.x).

A clogging determination device includes a first antenna disposed at one of a side of a first end and a side of a second end of a filter disposed internally of a case, a second antenna disposed at the other of the side of the first end and the side of the second end of the filter, a multi-tone signal generator that has an output terminal coupled to the first antenna, outputs from the output terminal a multi-tone signal obtained by compositing a plurality of signals having different frequencies, and moves a position of an envelope of the multi-tone signal emitted to the filter from the first antenna, a detector that is coupled to the second antenna, and detects an intensity of the multi-tone signal received by the second antenna, and a determinator that determines a degree of clogging of the filter based on an intensity of the multi-tone signal.

An exhaust gas control apparatus for an internal combustion engine includes an electromagnetic wave output unit, an acquisition unit that acquires collection amounts of PM and substances other than PM based on a rotational speed and a fuel injection amount of the internal combustion engine, and a control unit that controls an output intensity of the electromagnetic wave output unit. The control unit causes electromagnetic waves to be output with a first output intensity when the collection amount of the substances other than PM becomes equal to or smaller than a predetermined threshold, and causes electromagnetic waves to be output with a second output intensity that is lower than the first output intensity when the collection amount of the substances other than PM becomes larger than the predetermined threshold, when the collection amount of PM has exceeded a permissible value of the collection amount of PM in the filter.

A microcomputer includes a voltage application unit that selectively applies a normal voltage and a removal voltage higher than the normal voltage to a first cell of the exhaust gas sensor. The first cell is configured to remove, based on the removal voltage, oxygen in an exhaust gas from an internal combustion engine. The microcomputer includes an element temperature measurement unit that measures an element temperature parameter indicative of a temperature of the first cell. The microcomputer includes a termination determination unit that determines, based on the element temperature parameter, a termination time of terminating the application of the removal voltage to the first cell by the voltage application unit.

A species-specific gas sensor and monitor comprising a light source, a sample enclosure or measurement chamber, an optical interface between the light source, the sample and the detection system, electronics that integrate the light source and the detection system, and computational components, such as an onboard microprocessor for calculation of the gas composition and communications between the sensor and the vehicle electronics. The species-specific gas sensor of the present invention can be used to target gases, such as nitric oxide (NO), nitrogen dioxide (NO.sub.2) ammonia (NH.sub.3), and sulfur dioxide (SO.sub.2) which are measurable in the UV spectrum.

A heater system for an exhaust system is provided. The heater system includes a heater disposed in an exhaust conduit. The heater includes a plurality of heating elements disposed in the exhaust conduit. A heating control module controls the plurality of heating elements differently according to operating conditions specific to each heating element. In other forms, the heater system for an exhaust system has a plurality of heating zones, instead of a plurality of heating elements. The heating control module controls the plurality of heating zones differently according to operating conditions specific to each heating zone.

The present disclosure relates to a system and a method for removing noxious gas from cleaning liquid discharged from an exhaust gas treatment apparatus and, more particularly, to a system and a method for removing noxious gas from cleaning liquid discharged from an exhaust gas treatment apparatus, which are capable of adjusting the discharge rate of the cleaning liquid in a noxious gas removal unit, which removes noxious gas remaining in a gaseous state in the cleaning liquid discharged from the exhaust gas treatment apparatus and discharges the cleaning liquid from which the noxious gas in the gaseous state has been removed, on the basis of a result of measurement of the level of the cleaning liquid in the noxious gas removal unit.

A driving device includes a tubular circulation pipe of the exhaust gas, and at least two flow rate measuring members arranged to measure an exhaust gas flow rate circulating in the tubular circulation pipe. The driving device includes at least one monobloc support, housed in the tubular circulation pipe, and bearing at least two flow rate measuring members among said at least two flow rate measuring members.

Methods and systems are provided for diagnosing an active exhaust valve in an exhaust system based on thermal data. In one example, a method may include indicating degradation of a first active exhaust valve positioned in a first exhaust pipe of a first engine bank based on a difference between a first temperature of exhaust downstream of the first active exhaust valve and a second temperature of exhaust downstream of a second active exhaust valve positioned in a second exhaust pipe of a second engine bank. Degradation of the valve may be confirmed based on thermal image data acquired at outlets of the first and second exhaust pipes.

A device that includes a conduit, a first window, a second window, a first catalyzed layer, a second catalyzed layer, an optical source, and an optical detector is disclosed. The conduit may be configured to receive an exhaust gas. The first catalyzed layer may be disposed on the first window and the second catalyzed layer may be disposed on the second window. The first catalyzed layer and the second catalyzed layer may be configured to cause a reaction with soot in the exhaust gas at an activation temperature to reduce accumulation of the soot on the first window and the second window. The optical source may be configured to emit a beam of light into the conduit through the first window. The optical detector may be configured to receive at least a portion of the beam of light through the second window.