I'm sorry, but I disagree. An analog meter is much preferable to troubleshoot
car problems. You can watch varying voltages/currents/continuity that a DVM (or
DMM) can't. You can see any inductance/capacitance issues in wiring, if a diode
works properly, the timing of open/close of relays/switches much better. A DMM
is good if you REALLY know what you're doing, and already know and can
interpret analog actions into digital form.
As far as loading down a circuit, a meter is rated in ohms/volt. This is the
amount of parallel resistance the meter applies when you place the leads on the
terminals. BOTH the cheapy digital and analog versions are normally rated at
around 20K ohm/volt. More expensive meters are higher. The higher the better,
since less current is drawn through the meter and normally will mean more
accurate measurements. So a cheap analog meter won't load a circuit any more
than a cheap digital version.
I have both in my tool box, but gravitate to an analog version in most cases.
Thanks!
John
-----Original Message-----
From: ZinkZ10C@aol.com [SMTP:ZinkZ10C@aol.com]
Sent: Tuesday, October 12, 2004 11:34 AM
To: geneglenn@qwest.net; triumphs@autox.team.net
Subject: Re: DVM
In a message dated 10/12/04 12:26:44 PM Eastern Daylight Time,
geneglenn@qwest.net writes:
<< OK people: what's a DVM.
>>
Digital Volt Meter AKA DMM Digital Multi Meter
The advantage is no needle on the meter to get damaged, usually better
accuracy and no load placed on the circuit you are measuring.
The down side is since the meter does not load the circuit, stray voltage
will make you think the circuit has full power but it does not. If you are
measuring battery state of charge, a oxygen sensor or other computer car
sensor,
the DVM is better. If you are just trouble shooting a wiper circuit, a test
light is better because it load the circuit.
Harold
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