Clamp Meter Help

[squeak12 10+ year member]

I cant seem to work my clamp correctly. I cant get it to read any numbers like it should. I have it on AC amperage and max hold. What is something I could test it on that should give me a reading. I played a 45 Hz tone and it was reading something like 6 amps on a 2500D at 2 ohm.

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[JimJ 5,000+ posts]

Do you have the meter pointing in the right direction?

 

[squeak12 10+ year member]

Which was does it have to point? My manual just say clamp it around the wire.

 

[prochobo 10+ year member]

AC amperage you clamp around the speaker wires. DC amperage you clamp around the power wire. That may be your problem. . .

 

[BassAddictJ 5,000+ posts]

i had the same problem with mine.....

same meter as this one :http://cgi.ebay.com/Digital-CLaMP-MeTeR-DT266-Multimeter-w-Insulation-Test_W0QQitemZ300046234767QQihZ020QQcategoryZ52534QQrdZ1QQcmdZViewItem

and i couldnt get it to work right. the meter setting was correct (AC amperage).......so are you just suposed to clap it to the wire and thats it, anythign else?

 

[thch 10+ year member]

just 1 of the speaker wires, not both. if you wrap it around two wires, it really should read 0A as the net current flow through the loop is 0A.

 

[Ali1 10+ year member]

i have the same clampmeter... gave me the same problem like you guys.found out mine was broken, i just asked for a refund

 

[squeak12 10+ year member]

I have a craftsman. I clamped it around the speaker wire. Does it matter which one?

 

[prochobo 10+ year member]

I have a craftsman. I clamped it around the speaker wire. Does it matter which one?

Positive of course.

 

[squeak12 10+ year member]

Ill go see what I can do. Im not sure which one I clamped it around the first time. So anything on if it should be pointing in a direction, Jim?

 

[ngsm13 5,000+ posts]

Positive of course.

Doesn't matter which one. Uh Durr.

Also, the clamp meter other linked to on ebay... SUCKS balls. Throw it in the garbage.

nG

 

[squeak12 10+ year member]

I just went out and got some readings. It read these...

ACV 27

ACA 9.5

DCV 13.75

DCA 18

If Im wrong correct me but does that mean 256.5 watts at 2.8 ohm with 96.5% efficiency, because NONE of that seems right.

 

[danteBirosel 5,000+ posts]

how did u figure that out? (just curious..planing to get a clamp meter soon too)

 

[thch 10+ year member]

what type of amp?

it gives 256VA out. 247W in. assuming this is DC input to amplifier, AC output of amplifier.

there will be error on each measurement due to how the signals align.

power is RMS(V * I), which is equal or less then RMS(V)*RMS(I).

an explaination of how this could make sense mathmatically would be to look at an example where a person spins around, then walks 10ft. how far east-west has the person walked? the distance the person has walked (V*A in the analogy) is equal or greater then the distance the person has traveled in the east-west directions (real power in the analogy).

as shown, this gives 103% efficiency.

this is not a correct figure, but may be explainable due to the way class D amps handel inductive loads and the mentioned issues with volt-amps vs watts.

it does give that |Z| = 2.8ohm though. IMO thats the only thing a clamp+DMM should be used for.

edit:

if you have 95% efficiency in this case you would have 235W, 102VAR, giving an estimated impedance of 2.8ohm, +27deg. if you check winISD, you might be able to determine if this is reasonable to expect such an impedance and impedance phase. keep in mind this is under the assumption that the amp is 95% efficient and the measurements are correct.

 

[nVRuckus 5,000+ posts]

how did u figure that out? (just curious..planing to get a clamp meter soon too)

Im curious too I just received my meter today

I got one of these

http://cgi.ebay.com/Craftsman-True-RMS-Clamp-Meter-82014-Like-New_W0QQitemZ270051839618QQihZ017QQcategoryZ25412QQrdZ1QQcmdZViewItem