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AES
Product Article
Guidelines for choosing
a DSO or PGM
1.
What is your budget?
There is a meter for
every budget and inexpensive ones are not always bad.
Lower price tools such as the OTC Perception or the UEI ADL 7100 are both powerful and
versatile. More expensive meters, such as the Fluke 98 and the Interro PDA's, offer more
standard accessories and functions.
Also be sure to consider long-term value not just price. You don’t want to make the
mistake of purchasing a tool because it’s inexpensive then quickly outgrow it and
have to buy something else.
2. Are you looking for an oscilloscope or a power-graphing meter?
A digital storage oscilloscope is ideal for analyzing the
dynamics of any type of electrical signal, including primary and secondary ignition. The
DSO provides you with a waveform, which represents the actual characteristics of an
electrical signal.
A power-graphing meter provides a graph of a particular aspect the electrical signal. They
can graph many different characteristics of a signal such as voltage, frequency, duty
cycle, pulse-width, etc.
Examples of a DSO include the ADL 7100 and the Interro PDA. An example of a PGM is the
Snap-on Vantage (the Vantage does have a “waveform viewer” mode also). The
Fluke-98 and the OTC perception are both a DSO and a PGM.
3. What is your experience level with this kind of test equipment?
If you aren’t familiar with this type of equipment or
electronics in general, you may want to choose an instrument that has presets for
automotive use and/or a built in automotive database.
The Snap-on Vantage and OTC Perception both have built in, vehicle specific information
databases as well as automotive presets.
The Interro PDA has several automotive presets and a small waveform library.
The Fluke-98 has automotive presets, which are organized by the sensor or signal type.
Experienced technicians may find that the help menus and presets only get in the way. They
should stick with one of the more advanced meters such as the Fluke-98, Interro PDA or the
ADL 7100.
4. How willing are you to learn about the equipment and automotive diagnosis?
No matter what instrument you choose, there is quite a bit
to learn. We recommend educating yourself; you won't regret it!
You must be willing to take the time to learn:
* your meter's operation and characteristics,
* diagnostic strategies, and
* the systems being tested.
If time for education is limited then you should choose a tool such as the Snap-on Vantage
or OTC Perception which will walk you through the setup and testing.
If you are excited about learning automotive technology, then you’ll want to stick
with one of the more advanced tools such as the Fluke 98 or Interro PDA. That’s not
too say that the other meters won’t work for you, they’ll work just fine. You
just may not want to purchase a tool that you’ll quickly outgrow.
5. What type of testing will you be doing?
Every meter is perfectly capable of analyzing most
automotive electrical signals. Each also has some capability for analyzing ignition but a
full function engine analyzer such as the Interro PDA-100 is extremely powerful and easy
to use for ignition analysis.
6. Do you want a recording feature?
Every meter can save a screen in its memory, and some can
save a recording of a signal.
Recording a signal over time can be a very powerful diagnostic tool. The Fluke 98 and the
Interro PDA both have powerful recording and playback features. The Snap-on Vantage also
has some functions.
7. How many people will be using the tool?
If there will be several people using the same piece of
equipment, there may be a chance of it being abused, lost, etc. In that case, a lower
priced meter such as the UEI ADL 7100 or the OTC Perception may be a wise choice.
8. How often will you be using the equipment?
There’s no need to buy an expensive piece of
equipment if you are hardly ever going to use it. Of course, we recommend you use your
scope as often as possible.
Summary
Despite, what some people may tell you, every DSO or GMM
is good. They are all capable of providing information that is useful for diagnosis. When
people ask which one is the best, we can’t answer that question. You have to decide
which one is best meets your needs. No matter which piece of equipment you choose, it will
be useless unless you take the time to educate yourself about the tool and the systems you
are testing and develop an effective diagnostic strategy.
More on this subject:
Jorge Menchu has written a number
of articles on this topic, such as:
-- Which Scope/Meter is
Right for You? Motor Magazine, May 2001
-- Choosing a Lab Scope, Motor
Magazine, June 96
Click here for a complete list.
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