Thane Heins Perepiteia.

[polarbreeze]

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Here is the link to the meter we ordered: http://www.prova.com.tw/E_PROVA_11.html
Here is the link to the meter we have: http://www.prova.com.tw/E_CM_07.html

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Luc

Luc, you realize the Prova 11 has a measurement uncertainty of +/- 5 digits, right? I really think you should use a proper in-circuit meter for these tests, as also recommended by Mr Megger and others. It's important to remove the ambiguity in the readings. It's not important if there's voltage drop across the ammeter because you can measure the actual voltage entering the transformer with your voltmeter. This is really very fundamental research discipline - you need to make sure your test results withstand scrutiny otherwise there's no point in doing the tests. Please think very carefully about your choice here.

PB

[JustMe]

Luc, you realize the Prova 11 has a measurement uncertainty of +/- 5 digits, right? I really think you should use a proper in-circuit meter for these tests, as also recommended by Mr Megger and others. It's important to remove the ambiguity in the readings. It's not important if there's voltage drop across the ammeter because you can measure the actual voltage entering the transformer with your voltmeter. This is really very fundamental research discipline - you need to make sure your test results withstand scrutiny otherwise there's no point in doing the tests. Please think very carefully about your choice here.

PB

It sounded to me like he was saying the actual voltage ultimately output was changed by the presence of some devices at some settings, not that he had measurement problems with the voltage on the way in...?

[MeggerMan]

Hi Luc,
30% and 40% voltage drop, I cannot understand this?
I just checked the resistance of the 800mA and 10A ranges on my Tenma 72-7760 and it reads as follows:
800mA = 1.4 Ohms
10A = 0.14 Ohms

Max voltage drop on 800mA scale at 800mA:
V = I * R
V = 0.800 x 1.4
V = 1.12 V

Max voltage drop on 800mA scale at 10mA:
V = I * R
V = 0.010 x 1.4
V = 0.014 V or 14mV

Max voltage drop on 10A scale at 10A:
V = I * R
V = 10 x 0.14
V = 1.4 V

Max voltage drop on 10A scale at 10mA:
V = I * R
V = 0.010 x 0.14
V = 0.0014 V or 1.4mV

Anyway, I look forward to your results with a more sensitive clamp meter.

Regards
Rob

[OilBarren]

Luc, you realize the Prova 11 has a measurement uncertainty of +/- 5 digits, right? I really think you should use a proper in-circuit meter for these tests, as also recommended by Mr Megger and others. It's important to remove the ambiguity in the readings. It's not important if there's voltage drop across the ammeter because you can measure the actual voltage entering the transformer with your voltmeter. This is really very fundamental research discipline - you need to make sure your test results withstand scrutiny otherwise there's no point in doing the tests. Please think very carefully about your choice here.

PB

It sounded to me like he was saying the actual voltage ultimately output was changed by the presence of some devices at some settings, not that he had measurement problems with the voltage on the way in...?

YESTERDAY LUC SPENT 7 HOURS MAKING A NEW PRIMARY - NOW THAT HE HAS SORTED OUT WHAT WORKS AND WHAT DOESN'T. I BELIEVE HIS GOAL IS 200% WHICH SHOULD SILENCE ALL CRITICS.

THE UNIVERSITY IS AWARE OF OUR IMPROVEMENTS AND THEY WILL PEER REVIEW EVERYTHING IN DUE COURSE - SO IF WE ARE IN ERROR ANYWHERE IT WILL BE EXPOSED.

Thane

[OilBarren]

It's not important if there's voltage drop across the ammeter because you can measure the actual voltage entering the transformer with your voltmeter. PB

THE INLINE INPUT AMP METER CAUSES AN OUTPUT VOLTAGE DROP ON THE OUTPUT VOLTAGE ACROSS THE RESISTOR - WHICH DOES NOT OCCUR WITH THE CLAMP ON.

INSTEAD OF WAITING 10 DAYS OR SO TO GET ANOTHER METER LUC INTENDS TO MAKE THE MOST OF WHAT WE CURRENTLY HAVE - IT MAY TURN OUT TO BE THE WRONG APROACH IN THE END (ALTHOUGH IT DOUBT IT) - BUT NEVER A "WASTE OF TIME" SINCE WE ARE LEARNING VOLUMES EACH AND EVERY DAY ON WHY THIS TRANSFORMER DOES WHAT IT DOES - WHICH WE DON'T FULLY COMPREHEND AS YET.

Thane