Hi yes...
you're very right.
I was responding more to Neil's desire to have his old cheap meter again.

Got an inexpensive o-scope attachment for a lap top ?   That would be
great.

Just a matter of looking around I think .....I believe decent older used
generic oscilloscopes are out there.

here's a page of 'em on EvilBay.

http://www.ebay.com/sch/i.html?_trksid=p2043212.m570.l1311&_nkw=oscilloscope&_sacat=0

On 7/9/2012 9:51 AM, Larry Alofs wrote:
> Scott;
>    One of the main points that David was trying to make is that
> inexpensive analog meters have too low an impedance to measure the
> output of an O2 sensor.  They need too much current to operate and the
> sensor produces a volt or so, but a very small current.
> Imagine trying to measure the pressure in a small diameter brake line
> with a pressure gauge that allowed fluid to escape from the system
> thru a half inch opening.
>   A DVM generally has a high impedance (uses very little current to get
> its voltage measurement) but does not update quickly or smoothly and
> is therefore hard to interpret in this situation.  An oscilloscope
> will work, but is expensive and bulky.
>    What we need is an inexpensive o-scope attachment for a laptop.
> Would not need high frequency response by today's standards, just
> cheap and rugged.
>
> Larry A.
>
>
> On Sun, Jul 8, 2012 at 10:31 PM, Scott Daniel - Turbovans
> <scottdaniel@turbovans.com> wrote:
>> Inexpensive small analogue meters are like, only 5 or 6  bucks these days.
>> two gallons of gas about.
>>
>>
>>
>> On 7/8/2012 11:48 AM, neil n wrote:
>>> Good to know.
>>>
>>> Since I moved the AFM wiper to a new portion of resistive strip, I
>>> kind of assumed there would be no drop outs. Besides; moving the wiper
>>> did not change how the engine ran.
>>>
>>> Sure wish I still had my old $9 Radio Shack analogue meter!
>>>
>>> Neil.
>>>
>>>
>>>
>>> On Sun, Jul 8, 2012 at 11:35 AM, David Beierl <dbeierl@attglobal.net>
>>> wrote:
>>>
>>>> At 02:10 PM 7/8/2012, neil n wrote:
>>>>> With my DVOM, I'd see the value change at a more or less "even" rate
>>>>> when slowly and evenly moving the vane.
>>>>
>>>> The ideal tool for this is a scope.  Analog meter with a twitchy needle
>>>> is
>>>> next.  I'd rate most DMMs essentially useless for it unless they have a
>>>> fast-responding bar-graph display.  The normal 2-3 updates per second
>>>> really
>>>> can't show you little dropouts unless you're moving the vane with a
>>>> micrometer screw or something like that, .....
>>>> I'm going to make a wild guess that
>>>> a typical DMM is only actually looking at the input less than a quarter
>>>> of
>>>> the time.
>>>
>>>
>>> --
>>> Neil n
>>>
>>> 65 kb image Myford Ready For Assembly  http://tinyurl.com/64sx4rp
>>>
>>> '88 Slate Blue Westy to be named.
>>>
>>> '81 VanaJetta 2.0 "Jaco"  http://tubaneil.googlepages.com/
>>>
>>> Vanagon VAG Gas I4/VR Swap Google Group:
>>>
>>>
>>> http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines
>>>