×
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!
  • Students Click Here

*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

Jobs

Smoke Test

Smoke Test

Smoke Test

(OP)
I have heard the term "smoke test" as a diagnostic tool, but was not sure what it is for. Is it to measure the opacity of the vehicle exhaust or is it some sort of test to find air leaks into the passenger compartment?

RE: Smoke Test

Vacuum leaks

RE: Smoke Test

I think the EPA might have a smoke test for diesels. Failing one can be more problematic than failing an inlet manifold vacuum leak test.

I am sure the term can have many meanings depending on when and where.

Regards
Pat
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers &
http://eng-tips.com/market.cfm
for site rules
 

RE: Smoke Test

I have used cigar smoke blown through a small hose to check for clogs in carburetor passages, to bench-check the centering adjustment shims on a power steering control valve, and to verify correct installation of several large hydraulic lines spanning three compartments in a submarine.  That last test consumed an entire 'guinea stinker' and gave me a wicked headache.

 

Mike Halloran
Pembroke Pines, FL, USA

RE: Smoke Test

I can remember way back in about 1980 using a Bosch smoke tester for diesels.  It drew a sample through filter paper and then had some kind of optical meter that gave it a number.  It think it was a scale of 1 to 5.  Hopefully there is something more sophisticated today.

RE: Smoke Test

track air flow

fitting face masks
track ventilation effectiveness
find leaks

We used a lot of smoke when we built the new plant.  Check ventilation and employee training.

      

Thomas J. Walz
Carbide Processors, Inc.
www.carbideprocessors.com

Good engineering starts with a Grainger Catalog.    

RE: Smoke Test

Where is Cheech and Chong when you really need them..  Now that was some smoke!!

RE: Smoke Test

Don't they also use some kind of smoke during a wind tunnel test?

RE: Smoke Test

Pat - "smoke and mirrors", that would be automotive marketing.

RE: Smoke Test

Our HR department is mostly smoke & mirrors.

RE: Smoke Test

Certainly is...politicians have developed it to an art form!

Peter.

RE: Smoke Test

Bosch Automotive Handbook (5th Edition).  Page 566: "Smoke Emission Test Equipment"

It's all still based on blowing exhaust gases through a bit of tissue and seeing if it goes black or not.

- Steve

RE: Smoke Test

Hmmm, blowing cigar smoke through a gasoline carburetor.  Clever mechanical idea- but even more elegent procedure for simultaneously pushing ALL the buttons of a modern HSE (Health, Safety & Environment) department! winky smile

RE: Smoke Test

Some day I hope to work alongside Mr. Halloran, or at least spend a few evenings sharing a beer or two.  Drwebb, a star for pointing out the multiple hot buttons for HSE types.

In a long departed job we would use various "smoke analysers" for rocket exhaust plumes.  Seeing lots of iron, chromium, aluminum or other metal species in the exhaust was a sure sign that something was going (had gone) wrong.

RE: Smoke Test

I didn't say the carburetor was mounted on the car.  It was not.
It had in fact been completely disassembled and cleaned, with carburetor cleaner, then alcohol, then soapy water.
After which, some chalky deposits remained in the emulsification tubes, and some carbonaceous deposits remained in the transition jets.
Their presence was detected with the smoke.  
They were mechanically removed.
Their absence was verified by the smoke.
Then the carburetor was reassembled and reused in the normal way.

That (Ford/Motorcraft) carburetor would have given the HSE folks fits anyway; the normal procedure for adjusting the float level required measuring the float level with the entire top of the carburetor removed, on a running engine.  You were supposed to stop the engine to bend the float tangs, because bending them on a running engine would squirt gasoline from the float needle up into your face; this, I know.

 

Mike Halloran
Pembroke Pines, FL, USA

RE: Smoke Test

"I didn't say the carburetor was mounted on the car.  It was not."

Oh, Mike, don't spoil the legend.  

For some HSE types it wouldn't matter.  But this written in the manual would make the vision complete:  "Tuck lit cigar behind ear whilst adjusting the float level"

 

RE: Smoke Test

The "Smoke Test" is the first time an electrical device is powered up and is when the device is checked for leaks.

It apparently first originates with Lucas electrical parts and wiring looms. Paul Lucas is also known as the Pince of Darkness and credited with inventing the short circuit.

Most early British cars use Lucas electrics and when these fail is usually because of an escape of smoke.
It is noted that once the smoke escapes the circuit no longer works and the logical conclusion is that smoke is a vital component and if lost must be replaced in order to restore functionality.
For Lucas electrics there is a replacement smoke kit available:
http://www3.telus.net/bc_triumph_registry/smoke.htm

More recently it is a phenomena also associated with ICs where special blue smoke is used.

Google "Replacement smoke" and you will find a Wiki article called "Magic Smoke" plus many authoritative discussions of the phenomenon.
 

JMW
www.ViscoAnalyser.com

 

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!


Resources