使用光声技术测量极低烟尘浓度的新方法.pdf

1、Absorber Windows for Very Low Soot Mass Concentration using a Photoacoustic Instrument Imad Khalek,PhD,FSAEOSAR Conference,2024 1Project Team Imad Khalek,Institute Engineer Adam Aussi,Engineer Gina Buffaloe,Research Engineer2Background AVL Microsoot Sensor(MSS)is widely used for:Heavy-Duty In-Use Em

2、issions for EPA&CARB Aircraft Soot Mass Emissions as a part of the International Civil Aviation Organization(ICAO),where the USA is a member Emissions R&D in many other applications for soot measurement Motivation An Absorber Window Check is used to check instrument span Current Absorber Window chec

3、k is done at about 2-4 mg/m This is typically well above the actual measurement from the tailpipe of modern engines that is typically well below 100 g/m or even 50 g/m This is like spanning a gaseous instrument with 3,000 ppm and measuring at below 50 ppm An absorber window check in the range of mea

4、surement from 10 g/m to 100 g/m will be good for QA/QC 3Objectives Develop an absorber window for an AVL microsoot sensor for measurement in the range from 10 g/m to 100 g/m Make it simple and interchangeable with current absorber window without any additional modifications4Example of New Absorber W

5、indow Repeatability and Reproducibility,g/m5 We demonstrated the development of new absorber windows that can be used for QA/QC in the range of low soot emissions measurements from engines using MSSCheck 1 Check 2 Check 3 Average stdev COV,%W184798281.72.53.1%W288859087.72.52.9%W381838181.71.21.4%Ch

6、eck 1 Check 2 Check 3 Average stdev COV,%W151485049.71.53.1%W255484850.34.08.0%W350504749.01.73.5%Check 1 Check 2 Check 3 Average stdev COV,%W132272628.33.211.3%W230322729.72.58.5%W329272426.72.59.4%New Absorber Window Comparison with Two MSSs over 25 days of Daily Checks The COV ranged from 5.1%at