help with amp clamping...

[raptor727 10+ year member]

Hey guys I got a fluke 83III mm and a 87III true rms meter with clamp are these the correct meters for clamping?

Click to read more...

 

[raptor727 10+ year member]

Clamp is a fluke i1010 ac/dc current clamp

 

[raptor727 10+ year member]

Nothing really??

 

[Jepalan]

What are you trying to measure?

 

[raptor727 10+ year member]

Output watts and impedance rise...

 

[Jepalan]

Looks like those should work. To be honest, I have never tried to measure true RMS watts & calculate impedance rise, but I found a decent explanation on another forum...

"Use the True-RMS Clamp Meter on the +speaker wire only to measure your AC Amperage and use a DMM with peak-hold on to measure AC Voltage across the speaker +/- terminals.

Multiply those 2 numbers to get your RMS Wattage.

To find the Impedance rise you divide the voltage by the amperage. NOTE - impedance rise varies with frequency, so the measurement may depend somewhat on the test signal you are using. "

 

[dB-SPL 10+ year member]

That would be correct ^. And rise will be highest at your box tuning.

 

[n8skow 10+ year member]

Multiplying those number will give you VA - 'not' RMS wattage.

To get wattage, you would need to know the phase angle as well - which is a bit more involved...

For comparison purposes - VA is usually sufficient - just clarifying that the number you get is not the actual wattage.

Looks like those should work. To be honest, I have never tried to measure true RMS watts & calculate impedance rise, but I found a decent explanation on another forum...
"Use the True-RMS Clamp Meter on the +speaker wire only to measure your AC Amperage and use a DMM with peak-hold on to measure AC Voltage across the speaker +/- terminals.

Multiply those 2 numbers to get your RMS Wattage.

To find the Impedance rise you divide the voltage by the amperage. NOTE - impedance rise varies with frequency, so the measurement may depend somewhat on the test signal you are using. "

 

[RangerDangerV2 5,000+ posts]

That would be correct ^. And rise will be highest at your box tuning.

not always true, but most of the time. @37hz I rise to 12.16 ohms, but at 54, which is what im tuned to, I rise to 7.745 ohms, and my peak, which is 41hz, I rise to 6.394 ohms. LOL

 

[naughtyca 10+ year member]

Looks like those should work. To be honest, I have never tried to measure true RMS watts & calculate impedance rise, but I found a decent explanation on another forum...
"Use the True-RMS Clamp Meter on the +speaker wire only to measure your AC Amperage and use a DMM with peak-hold on to measure AC Voltage across the speaker +/- terminals.

Multiply those 2 numbers to get your RMS Wattage.

To find the Impedance rise you divide the voltage by the amperage. NOTE - impedance rise varies with frequency, so the measurement may depend somewhat on the test signal you are using. "

can you recommend a cheaper clamp meter?

 

[n8skow 10+ year member]

fluke 902 | eBay