Blow-By Measurement

The NEW Blow-By Test Rig BBT 143 is a compact measuring system for the determination of the oil droplet content of crankcase gases (blow-by) at engine test rigs. It combines the precision of a gravimetric measurement of the GMS 141 with the speed of an optical concentration measurement of the aerosol photometer PAP 610.
Because of the design of the blow-by test rig and of the stand-alone devices, these measurements can be performed very efficiently at engine test stands. Combining the Gravimetric Measuring System GMS 141 with the Process Aerosol Photometer PAP 610, oil consumption measurements for engine characteristic maps can be performed with minimum efforts and time.
Additionally, the phototmeter PAP 612 provides the opportunity to measure oil films and oil gushes in pipes e.g. at tilt test stands.

The compact Gravimetric Measurement System GMS 141 allows the comfortable detection of oil content in blow-by after oil mist separators with a filter flat sheet or filter cartridge directly on engines or engine test stands. The measuring device combines a simple and robust assembly with an economic low-cost manual or automated application and handling.

The Process Aerosol Photometer PAP 610 was developed for on-line concentration measurement of blow-by aerosols. This measuring instrument is an addition to the Gravimetric Measuring System GMS 141. A highly concentrated aerosol passes through an extinction of light arrangement and causes a light decrease of the incident light in propagation direction. On the basis of this decrease the concentration of the oil droplets in the blow-by aerosol can be determined after a gravimetric calibration of the signals of the photometer.

The Process Aerosol Photometer PAP 612 is a combined on-line extinction and scattered-light photometer with double-running test sections and two wavelengths, which can operate in overpressure or underpressure e.g. for measurements of gushes of oil. Besides high concentrations of oil in the blow-by, it can detect wall films in pipes. Due to its compact design, its use is conceivable on test rigs for engines, on swiveling test rigs, under lab conditions as well as for test drives in field use.

For testing oil mist separators/crankcase ventilation systems Topas GmbH has developed the Oil Mist Separator Testing System SPT 140. It is particularly suited for characterisation of diverse separators for blow-by aerosols  in combustion engines. Following analysis can reliable be done by means of the test rig with a low expenditure of time:

• Gravimetric efficiency measurements and fractional separation determination,
• Determination of discharge curves (pressure loss over volume flow rate),
• Determination of pressure regulation curve and leackage.

The test rig simulates several operational conditions of typical application fields of oil mist separators.
During determination of discharge curve the “crankcase ventilation system pressure” is measured in depence from intake pressure for different volume flow rates.