×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

exhaust sampling

exhaust sampling

exhaust sampling

(OP)
hi!!

i am trying to measure PM emssions from a DI diesel engine. my experimental set-up consits of a vacuum pump which and a flow controller to draw in exhaust into the sample chamber of the PM emssions instrument. the set value for the flow rate of exhaust is 5 SLM. but the actual exhaust flow rate seems to be exceeding the set flow rate. a lot of exhaust is flowing through the sampling tube. i guess the pressure of the exhaust is too high. also the exhaust flow rate in the sampling tube varies with engine speed. how do i sample the exhaust so that the flow rate stays at 5 slm and the sampling method does not affect teh PM in the exhaust sample? i was thinking of using a flow meter before the sample chamber. but the flow rate will still vary with engine speed and i am not sure if the floe meter will affect the PM.  is there a cheap and easy way to fix this problem?

thanks!
ales

RE: exhaust sampling

It sounds as though the back pressure of the exhaust downstream of your sampling point is too great. You could put a small orific plate or a throttle flap into your sampling tube, between the flow limiter and the exhaust, or you could move your sampling point further down the exhaust, or fit a free flowing exhaust.

Cheers

Greg Locock

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login



News


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close