The demand for cleaner air emitted from cars is increasingly determining the exact test technology required and the associated growing requirements on measurement technology. The ultrasonic technology from SICK has proven itself in a wide range of requirements on exhaust gas flow measurement in vehicle test stands. Practical tests prove: FLOWSIC150 Carflow is highly precise in the measurement of very short response times.
In addition to exhaust gas analysis, high-accuracy volume flow measurement is the foundation for efficient optimization and advancement of vehicle motors and off-gas systems. A whole catalog of requirements for exhaust flow meters must be fulfilled before the measurement device can be considered ideal for test bench applications in the automotive industry: Real-time capability, a wide measuring range at high resolution, high temperature resistance, low pressure loss, low-maintenance operation and maximum measurement accuracy even under dynamic flow and at very low flow rates. The measurement is complicated by the flow condition in the exhaust of internal combustion engines, which greatly depends on operating conditions and is subject to high dynamics. Pulsations when idling also appear like highly turbulent flows and very low flow velocities.
Due to ever-shorter vehicle development cycles and the enormous challenge of meeting future emission limits, direct volume measurement of exhaust gases is becoming increasingly crucial in vehicle development. FLOWSIC150 Carflow offers a key technology for this purpose.
Direct measurement has a big future
Motors are developed with modern combustion processes and complex exhaust gas treatment systems. The costs to assess the potential of and to coordinate these concepts in regards to emissions performance and on-board diagnostics are significant. Therefore, these studies begin in a development stage where sometimes no emission results can be determined on the exhaust roller dynamometer test bench. Engineers are searching for ever smaller optimization potentials which are of great importance for simple and accurate determination of time-resolved pollutant processes. State-of-the-art measurement techniques such as direct ultrasonic flow rate measurement can generate the required data and are an important contribution to the development and optimization of new generations of engines.
Direct exhaust gas flow measurement has significant advantages over the alternative calculation of the exhaust volume flow from other measurands or model approaches; practical test have shown this. The measurement error increases when calculating from various measurands on the one hand, and on the other, model approaches are often limited to specific system environments. Therefore, direct measurement of the exhaust flow rate represents the simplest, most precise method.
Compact and capable
With measures in the area of flow conditioning and the use of state-of-the-art sensor technology in the 4-path design, independence from the flow pattern control, the zero-point stability and small quantity measurement is being further optimized. The patented sensor cooling enables the application of the device to exhaust temperatures up to 600 °C and at the same time ensures a long service life of the ultrasonic sensors through optimal thermal management.
The FLOWSIC150 Carflow is available as a mobile dynamometer wagon in a compact design and is ideally-suited for flexible exhaust gas flow measurement on exhaust gas and chassis dynamometers.
With the FLOWSIC150 Carflow, SICK has offered an ultrasound exhaust flow meter for test bench applications for more than 15 years. The device was developed in collaboration with leading automobile manufacturers and has been continuously optimized since the time of its launch. The focus was to improve metrological properties while expanding its field of application. The current device generation of the FLOWSIC150 Carflow takes advantage of the most recent SICK ultrasonic technology which the sensor manufacturer, one of the leading vendors of industrial exhaust gas flow technology, has been using with great success.