Car exhaust pressure and gas flow measurement?
Car exhaust pressure and gas flow measurement?
(OP)
What type of sensor is best suited to measure pressure in the exhaust (muffler) at high temperatures of the exhaust (around 1000F)? I want to measure the pressure at different points of the exhaust and see how they change as engine rpm varies. Which sensor do you recommend? What is the range of pressure of a typical engine?
Would a pitot tube be adequate to measure the air flow (velocity) also for high temperature application? What manufacturer would you recommend?
I think the exahust of a gasoline and diesel engine can reach 1200 deg F.
Would a pitot tube be adequate to measure the air flow (velocity) also for high temperature application? What manufacturer would you recommend?
I think the exahust of a gasoline and diesel engine can reach 1200 deg F.





RE: Car exhaust pressure and gas flow measurement?
You shouldn't see more than 1 bar gauge pressure unless the exhaust system is REALLY bad.
Andy
RE: Car exhaust pressure and gas flow measurement?
RE: Car exhaust pressure and gas flow measurement?
Which pressure transmitter have you used? I want to collect data and pick them up from a computer. I guess I can use Labview for data acquisition, but this is kind of expensive. Have you seen cheaper alternatives?
Know anything about pitot tubes used to measure flow (velocity) in the exhaust?
thanks
wsjoe
RE: Car exhaust pressure and gas flow measurement?
I'm afraid I've never attempted to measure flow in the exhaust, but I think the best way would be to measure pressure before and after a laminer flow element (like a catalyst) after calibrating on a flow bench.
Andy
RE: Car exhaust pressure and gas flow measurement?
As far as a sensor goes, I have found that if you go down to the local scrap yard and find a boost sensor from a turbo vehicle. These work well as they usualy work off 5 volts (some 12 volts battery voltage). They are generaly 3 wire sensors -volts +volts and a signal out.The nice thing about them is that they have amps, filters etc already built in so the signal out is clean and repetitive.
RE: Car exhaust pressure and gas flow measurement?
Andy do you use any liquid to isolate the exhaust gas from the sensor element? When I did my install I used 14” of ¼” tubing bent in an S shape. I filled the last 8” with 10w shock oil because I was scared that the sensor would have a short life when exposed to high temp exhaust gas and also to trap any soot particles. I’ve only had it in the car for about two months but so far all is well.
RE: Car exhaust pressure and gas flow measurement?