Abstract: A gas dividing and blending system including a gas divider for generating a mid-span gas for more than one analyzer at the same time so that the analyzers can run their mid-span checks at the same time. A mid-span gas is generated using the span gases for the analyzers. If desired, a separate diluent gas may also be mixed with the span gases to generate a mid-span gas. Once a mid-span gas is generated, it is then simultaneously delivered to each analyzer which uses the mid-span gas to perform its mid-span gas check at the same time as the other analyzers.

Abstract: Subsonic venturi proportional and isokinetic sampling methods and apparatus for use in evaluating exhaust emissions from an exhaust source which utilizes a pair of calibrated subsonic venturi restrictions for measuring the bulkstream and extracted sample flow rates respectively. The subsonic venturis may be specifically configured relative to each other to provide isokinetic sampling under specified control conditions.

Abstract: A frictionless bearing chassis dynamometer including a pair of laterally spaced-apart rolls adapted to be engaged and driven by a pair of wheels of a vehicle. A power exchange unit is disposed between the rolls and includes an input shaft fixedly coupled to each of the rolls. The input shaft is supported at its opposite ends by bearing assemblies which each include inner and outer annular bearings and an inner/outer race member disposed therebetween, which forms an outer race for the inner annular bearing and an inner race for the outer annular bearing. Independent bearing motor drive assemblies are coupled to each of the inner/outer race members by independently drivable bearing drive hubs, pulleys and drive belts.

Abstract: A novel extended lifetime scintillation camera plate assembly and method for manufacture thereof is disclosed, the assembly comprising a body having a plurality of scintillating elements to receive the incoming radiation and produce light, and a plurality of light conducting elements coupled to the scintillating elements to receive and guide the light, and a frame which is sealed around the body by means of solder or laser weld joints thereby eliminating the need for temperature and moisture unstable epoxy resin sealing techniques.

Abstract: An exhaust sampler for use in evaluating exhaust emissions of an exhaust source such as an internal combustion engine which utilizes a calibrated subsonic venturi for measuring the exhaust or exhaust/dilution air flow rate. Controls are provided for selecting and controlling a variety of flow rates between or during test periods. The system also provides a variety of control methods for extracting a sample from the bulkstream flow of exhaust and dilution air or from raw exhaust flow.

Abstract: A testing apparatus for sampling the emission content of the source when a portion of the exhaust gas is optionally diluted using clean dry air added near the sample extraction point. A sonic venturi is used to establish a constant mass flow rate from the exhaust system of the engine under test and a subsonic venturi monitors the flow rate of dilution air. Both venturis provide flow rate signals which are substracted to determine the flow rate of the exhaust.

Abstract: A torque measuring device having dual range load cells is provided featuring high accuracy over a large range of torque measurements. A pair of load cell assemblies act on the torque arm of a dynamometer torque balance. A compliant element is employed to connect the torque arm to a low range load cell assembly and lost motion means are provided by the high level load cell assembly. Low torques imposed on the torque balance cause only the low range load cell to be loaded. The low range load cell assembly is selected to provide high accuracy over the low torque range levels. Once a predetermined threshold torque is applied, the deflection of the compliant element permits the torque arm to engage the high level load cell assembly. Torques beyond the threshold level are determined by summing the measured torques of both load cell assemblies.

Abstract: An improved mechanical flywheel assembly for a chassis dynamometer. The flywheel assembly includes a plurality of flywheels journalled to a stationary shaft located within a cylindrically-shaped drum that is directly coupled to the rollers of the dynamometer so that the drum rotates at the speed of the rollers. Each of the flywheels has an air-actuated clutch mechanism secured around the periphery of the flywheel so that upon actuation, the clutch mechanism expands radially sufficiently to engage the inner wall of the drum and thereby cause the associated flywheel to rotate with the drum. Means are disclosed for controlling the selective actuation of the various clutch mechanisms to thereby selectively control which of the various flywheels are engaged.

Abstract: A testing apparatus for measuring the particulate and/or gaseous content of an exhaust source for use in evaluating the exhaust emissions of internal combustion engine provides both fixed flow and proportional flow control of the diluted particulate containing sample. The sample is diluted with carefully metered, clean dry air by means of one or more hybrid electrical-fluid control circuits for remarkably improved response time and accuracy.

Abstract: A testing apparatus for measuring the particulate and/or gaseous content of an exhaust source for use in evaluating the exhaust emissions of internal combustion engine provides both fixed flow and proportional flow control of the diluted particulate containing sample. The sample is diluted with carefully metered, clean dry air by one or more hybrid electrical-fluid control circuits for remarkably improved response time and accuracy.

Abstract: A vehicle force measurement system for determining the force output of a vehicle independent of the radius dimensions of the driving wheels of the vehicle. A fifth wheel is utilized to provide an accurate vehicle speed reading. Torque and RPM sensors mounted to the driving wheels of the vehicle are used to determine the total power output of the vehicle and the total force output of the vehicle is determined by dividing the total power output by the speed signal from the fifth wheel.

Abstract: A dynamometer system for simulating road load and vehicle inertia forces for testing vehicles in place. The system includes a DC motor power absorption unit (PAU) and a microcomputer based system controller for controlling both the road load and inertia forces simulated by the PAU. A non-declutchable flywheel is used to simulate mechanically a constant amount of inertia to minimize the power requirements of the PAU. The control scheme is designed to implement the classic dynamometer control expression (F=A+Bv+Cv.sup.2 +I dv/dt) in a novel manner with a minimum amount of delay time. The microcomputer is provided with the following measured functions: speed, acceleration, and a torque signal. The total force output to be simulated by the PAU is determined by first calculating the actual force output of the vehicle, and then determining the percentage of the total force output that should be assigned to the PAU.