multi-meter issue

[Hebert]

someday I will get a high-quality multi-meter. today the problem with my current meter is that it will not zero out and starts ac volts at 1.5 or 2v. my rectifier heaters are testing at 7v and my heater wires are 8.1. Is it possible that the voltage that I am testing is being added to the 1.5 or 2v? or are my voltages quite a bit off from what they should be?  thanks
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[DummyLoad]

have you tried a new battery? 


--pete

[Hebert]

have you tried a new battery? 

that could be the problem. I will try that but I am still wondering if a value starts off at say 2v rather than zero is that amount added to the result of a test?

--pete

[shooter]

if a value starts off at say 2v rather than zero is that amount added to the result of a test?

you don't add or subtract, you call the test invalid

aside;
the reason test equipment has calibration certificates is so you as the tester can calibrate or certify equipment, I would NEVER initial it good with unknown test equipment.
even in hobby work, if my meter can't measure a car battery or my wall power, how can I calibrate, or build an amp

[jjasilli]

It is normal for multimeters to show a voltage reading when unconnected. Google:  "multimeter shows voltage when not connected" for lots of info.  The meter should -0- when you touch the leads together. 


It's a good idea to have more than one DMM; like having 2 compasses if you go hiking. 


When you measure voltage in an amp, you must specify if the circuit is loaded (tubes in) or unloaded (no tubes).  Unloaded circuits will have a higher voltage.  Also, the age of your amp.  Vintage trannies expect a wall voltage as low as 110VAC.  If you feed-in today's 120+VAC, there will be a commensurately higher secondary voltage.

[ALBATROS1234]

What makes you think your dmm is reading wrong? In my experience 7volts is an average reading. Theorhetically the transformer designwrs are shooting for 6.3v @ 120v wall power. Vintage were designed for 110v. So anything older than 40 years ago plus will read high. Plus what is your wall voltage if its higher or not exactly 120v  you will be slightly off. My wall power has varied as much a 118v to 124v depending on the day. So you secondary voltages will also vary. 7 volts is not going to hurt anything anyway. Thats only .7 of a volt off.perfectky acceptable normak variance.

[sluckey]

What makes you think your dmm is reading wrong? In my experience 7volts is an average reading. Theorhetically the transformer designwrs are shooting for 6.3v @ 120v wall power. Vintage were designed for 110v. So anything older than 40 years ago plus will read high. Plus what is your wall voltage if its higher or not exactly 120v  you will be slightly off. My wall power has varied as much a 118v to 124v depending on the day. So you secondary voltages will also vary. 7 volts is not going to hurt anything anyway. Thats only .7 of a volt off.perfectky acceptable normak variance.

Read his post too fast?   

His 5v is reading 7v. His 6.3v is reading 8.1v. Is that acceptable to you? Not me.

[shooter]

Not me

might get by a couple reports, but guessing you'd get fired for fudging soon enough 

[PRR]

What IS your present meter? It is unusual now to have a "zero out" on a meter; but they still sell needle-meters. When dropped (or made too cheap), they don't zero-out, and can't be fixed.

Useful digital meters can be had for under $20 shipped on Amazon; under $30 at Home Depot.