Article Categories

»	Arts & Entertainment
»	Automotive
»	Business
»	Careers & Jobs
»	Education & Reference
»	Finance
»	Food & Drink
»	Health & Fitness
»	Home & Family
»	Internet & Online Businesses
»	Miscellaneous
»	Self Improvement
»	Shopping
»	Society & News
»	Sports & Recreation
»	Technology
»	Travel & Leisure
»	Writing & Speaking

Reprint Article Code

Category: Articles » Automotive » Article » Article Code

Logging the data received from the dynamometer

On old-fashioned dynamometers, the operator or the observer had to manually record the simultaneous readings on paper. Nowadays, most dynamometers replace the observer's notes with computerized devices that acquire and store the data. Because of the very loud noise generated by the dynamometer and the engine, a performance test is stressful to anyone who's watching it. In these given conditions, it is very difficult to manually record all the data. A reliable computerized data acquisition system is considered to be indispensable today among engine builders and testers. Nowadays it is possible to buy recording, control, and playback ... read more

Article Title:

Article Body:

On old-fashioned dynamometers, the operator or the observer had to manually record the simultaneous readings on paper.

Nowadays, most dynamometers replace the observer's notes with computerized devices that acquire and store the data.
 
Because of the very loud noise generated by the dynamometer and the engine, a performance test is stressful to anyone who's watching it. In these given conditions, it is very difficult to manually record all the data.

A reliable computerized data acquisition system is considered to be indispensable today among engine builders and testers. Nowadays it is possible to buy recording, control, and playback capabilities in a palm sized package, that many years ago would have cost a lot more and would have had the size of a refrigerator.
 
An appropriate computerized data acquisition system must have a very fast sampling rate. For obtaining quality data, you will need at least 100 samples, of all sensor channels, per second (100Hz). A 200Hz logging rate or more is even better. It is important to remember that between spark plug firings there is a drop in torque and rpm that can be measured. The crankshaft is accelerated right after combustion occurs and afterwards it slows down until the plug will fire one more time. It is not possible to detect these rapid highs and lows when you are driving on the track or on the road, but the dynamometer will.
 
Therefore, a 200 Hz logging rate for your data acquisition system should do the trick, as well as an appropriate dynamometer.
 
However, if you sample at only 50Hz, you should consider that you are recording a single torque and rpm sample every other revolution. From time to time, a series of samples will synchronize with the firings of the plugs, and sometimes the data samples will fall in synch with some lower power compression strokes. If you are using a fast and reliable acquisition system that read each cycle multiple times, then the data captured can be used to average out the given phenomenon.

Averaging the data is a very important step in data acquisition.
 
At this point, while experienced dynamometer operators see an identical power curve in both graphs, inexperienced dyno operators expect to see a smooth, clear line.
 
The reason why the ability to average and dampen the data is essential for the acquisition system is that you don't have to deal with so many printings.

For instance, at 100Hz you're getting 1000 lines of data for even a ten-second dynamometer pull. You might choose not to search for any small changes in dozens of pages of data every time you want to prepare another run. Averaging both eliminates transient noise and produces clear printouts, and thus it is very useful in the process of logging the data from the dynamometer.

Author Bio:

Some other recently published automotive articles

Fresh, Up-To-Date Automotive News by Hernard B Garcia
That's right; the meeting place for all car fans is available by pointing your browser to automotive.media57news.com, the blog where fresh and up-to-date automotive news is cooking every single ...

Is DaimlerChrysler Facing Divorce? by Anthony Fontanelle
It was a marriage heard around the world. In November 1998, a stunning $36 billion merger was perfected between Daimler Benz, the German manufacturer of Mercedes-Benz ...

Displaying Personal Number Plates Legally by Ross O'Donnell
Whether it is a name, word or date, most personal number plates read exactly what the owner intended. However, as personal numbers plates are unique, only one person can own the "proper" plate. A minority of people ...

How to get your kind of RV by Alfred Anderson
A Recreational Vehicle that fails to serve your purpose not only mars your vacation but also is a loss of time and money. However finding the right RV is not a very easy task. ...

Mobile Phones and Driving by malcolm forster
Judging by the number of people I still see using mobile phones whilst driving it would seem very few people are aware that the The Road Safety Bill received Royal Assent on 8th November 2006. ...

Less than 150,000 Jeep Grand Cherokee Units Sold in the USA During 2006 by Al Harris
With the introduction of the first Grand Cherokee, Jeep defined and created the luxury sport utility vehicle (SUV) market, but in spite of this grand tradition the model is currently ...

Publisher Guidelines

You may reprint this article electronically in your newsletter or on your website, free of charge.

If you reprint this article from our site, then you must keep everything intact. This includes the articles title, author name, articles body, authors bio / resource box, the links contained within the article, all copyright notices and the link pointing back to our site. All links within the article must also be made active / hyperlinks.