An emissions measurement system capable of providing an accurate, real-time estimate of particle number (PN)/particulate matter (PM) within exhaust is disclosed. The system is capable of accurately differentiating the size and composition of PM/PN by synchronizing dissimilarly configured sensors. The exhaust may be generated by an internal combustion engine, in which case the system may be sequentially connected to the exhaust from the internal combustion engine.

An abnormality detection device determines abnormality in an exhaust gas sensor, disposed in an exhaust passage of an engine to detect a component in exhaust gas. The abnormality detection device includes: a responsiveness determination unit configured to calculate responsiveness of the exhaust gas sensor on the basis of a timewise change of output values of the exhaust gas sensor; and an abnormality determination unit configured to determine that the exhaust gas sensor has abnormality when the responsiveness calculated by the responsiveness determination unit is lower than a predetermined responsiveness threshold. The abnormality determination unit determines if the exhaust gas sensor has abnormality, excluding an excluded period during which a slope of the output values becomes zero or is inversed with respect to a preceding trend of the timewise change while the output values of the exhaust gas sensor timewisely change between a predetermined first and second determination values.

A mobile compressed natural gas (CNG) vessel and unloader are used to supply CNG to a compressor during regulatory emissions testing of the compressor (e.g., U.S. EPA's Quad J testing). CNG output by the compressor is recirculated to an inlet of the unloader so that it is reused during the emissions testing. Lean CNG from the vessel may be used to power the compressor during the testing. The unloader ensures that the compressor is run at at least a predetermined load factor during the emissions testing.

Methods and systems are provided for detecting NOx sensor degradation based on results from a NOx sensor self-diagnostic (SD) test performed after a key-off event. In one example, a method may comprise waiting a duration to perform a SD test of a NOx sensor after a key-off event until engine operating conditions stabilize and reach a set of qualifying conditions. One or more SD tests may be performed after waiting the duration, but outputs generated under conditions where one or more of a temperature at the sensor is greater than a threshold, and an oxygen concentration is outside a threshold range, may be excluded when determining whether or not the NOx sensor is degraded.

A diagnostic system and method for diagnosing the performance of a particulate matter (PM) filter of an exhaust system each involve receiving, by a controller from at least one sensor, a gas component measurement of exhaust gas flowing through the exhaust system and the PM filter. The controller calculates a conversion efficiency of the gas component by the PM filter and compares the calculated conversion efficiency to a predetermined conversion efficiency threshold indicative of an expected conversion efficiency of a flow-through catalyst. The controller then determines whether the PM filter is cracked or damaged based on the comparison between the calculated conversion efficiency and the predetermined conversion efficiency threshold.

Methods and systems are provided for predicting response time of a particulate matter (PM) sensor and resetting the PM sensor upon completion of response time prediction, independent of actual or predicted soot load on PM sensor. Soot accumulation data collected during steady state vehicle operation may be fitted with a time-based polynomial function and sensor output and regeneration schedule may be estimated from the curve fit even if the overall signal is noisy.

A chemical species mass flow meter measurement system for use in fluid mixture streams includes a chemical species concentration detection analyzer physically located within a fluid volume flow rate sensing probe along with bulk temperature and pressure sensing devices for relating to standard conditions. The system uses concentration detection analyzers specifically suited to the intended application. Applications include the measurement of exhaust mass emissions from vehicles, the fuel economy of vehicles, as well as the measurement of the mass flow rate of chemical species of interest in general industrial processes.

An abnormality diagnosis system of an internal combustion engine which is provided with an exhaust purification catalyst 20 which can store oxygen is provided with a downstream side air-fuel ratio sensor 41 downstream of the catalyst and a catalyst abnormality diagnosis system which uses an output air-fuel ratio of the downstream side air-fuel ratio sensor when performing active air-fuel ratio control as the basis for diagnosing an exhaust purification catalyst for abnormality. The catalyst abnormality diagnosis system uses the amount of oxygen which is stored in or released from the exhaust purification catalyst in an air-fuel ratio reversal time period in active air-fuel ratio control as the basis to calculate the maximum storable oxygen amount of the exhaust purification catalyst and uses this as the basis to diagnose the exhaust purification catalyst for abnormality.

In an apparatus and system for monitoring and communicating emissions data for a diesel engine, an exhaust gas analyzer uses laser light passed through a diffuser to measure the quantity of trace gases and particulates in an exhaust gas outlet from a diesel engine. The analysis chamber possesses superhydrophobic, superhydrophilic, and/or superoleophobic properties to reduce VOC-occlusion of the transparent chamber walls. A radio transmitter, cellular data transmitter, or Smartphone transmits measurement data. In a diagnostic and monitoring system for a diesel engine, the exhaust gas analyzer is in contact with the exhaust gases from the diesel engine, preferably in the tailpipe. A data receiver receives the transmitted measurement data.

A method of detecting flame state of a combustor of a turbine engine. The method includes determining at least one of a first derivative and a second derivative of a compressor discharge pressure of a compressor of the turbine engine; determining at least one of a first derivative and a second derivative of a gas turbine exhaust gas temperature of the exhaust gases output by the turbine engine; determining at least one of a first derivative and a second derivative of a gas turbine shaft/rotor speed of the turbine engine; determining at least one of a first derivative and a second derivative of combustor dynamic pressure monitoring; and determining a flame state of a combustor of the turbine engine based on the combustor dynamic pressure monitoring, the determined derivatives of the combustion dynamics, compressor discharge pressure, gas turbine shaft/rotor speed, and gas turbine exhaust gas temperature of the exhaust gases.