Abstract: A system according to the principles of the present disclosure includes an engine control module, a valve control module, and a level determination module. The engine control module controls an engine mounted in one of an engine dynamometer and a chassis dynamometer based on a predetermined schedule specifying a desired speed with respect to time. The valve control module controls a valve to inject a first quantity of a substance into an exhaust system to simulate the engine outputting an emission. The level determination module determines an emissions level of the emission in the exhaust system based on the predetermined schedule and the first quantity.

Abstract: A system according to the principles of the present disclosure includes an engine control module, a valve control module, and a level determination module. The engine control module controls an engine mounted in one of an engine dynamometer and a chassis dynamometer based on a predetermined schedule specifying a desired speed with respect to time. The valve control module controls a valve to inject a first quantity of a substance into an exhaust system to simulate the engine outputting an emission. The level determination module determines an emissions level of the emission in the exhaust system based on the predetermined schedule and the first quantity.

Abstract: A method for calibrating a plurality of gas analyzers includes providing gas analyzers that measure the concentrations of gases. A span gas includes a mixture of the gases. A calibration mixture is supplied to the gas analyzers that includes the span gas and a non-reactive zero gas. At least one of a concentration of the non-reactive zero gas and a concentration of the span gas is varied in the calibration mixture as a function of time. The gas analyzers generate sets of readings of the concentrations of the gases. A controller generates response functions of the gas analyzers based on the sets of readings. The controller determines exact concentrations of the gases in the calibration mixture based on a set of readings from a gas analyzer with a predetermined response to a gas. The controller calibrates the gas analyzers based on the response functions and the exact concentrations.

Abstract: A method of simulating a cold start automobile emissions test on an automobile is provided. The automobile includes an emissions system. The emissions system includes an engine and at least one catalytic converter. The automobile is preconditioned. A first gaseous substance is injected into the emissions system of the automobile between the engine and the catalytic converter. The first gaseous substance is further injected into the emissions system of the automobile after the catalytic converter. The engine of the automobile is then started. Finally, a second gaseous substance is injected into the emissions system of the automobile.

Abstract: A gas flow system for an emission analysis bench includes a source of blended calibration span gas using a single span tree connected with all the analyzers so that a method of simultaneous calibration or diagnosis of all the analyzers may be carried out and the need for multiple span trees connected with various separate span gases is avoided. The method includes concurrent delivery of one or more divisions of the span gases to all the analyzers to obtain intermediate data points from the analyzers. A further step of using a precalibrated or linear analyzer, such as the flame ionization detector (FID hydrocarbons analyzer) of the system, to accurately determine the percentage ratio of intermediate divide points obtained by mixing various amounts of zero gas with the span gas simplifies the calibration procedure and eliminates the need for an expensive gas divider.

Abstract: A mini-diluter apparatus and method are provided for preparing dilute samples of exhaust gas for emission testing. The apparatus includes first and second mass flow controllers which respectively control the mixing of exhaust gas and diluent gas samples at a constant ratio. The mixture is fed at a pressure, controlled by a back pressure regulator, to a third mass flow controller. This third controller provides a controlled sample rate (normally proportional to exhaust flow from an engine under test) to a bag sample system, or other sampling system, with excess mixture being exhausted through a pressure regulator to atmosphere. Improved accuracy and reduced calibration complexity are results of the improved apparatus and method.