# How is burden measured? [closed]

How is burden measured for the secondary circuit of either a current transformer or potential transformer? Also, is there a test set made for measuring burden?

• What is "burden"? – Leon Heller May 6 '13 at 20:12
• Do you mean burden voltage? en.wikipedia.org/wiki/Multimeter#Burden_voltage – jippie May 6 '13 at 20:48
• I suspect he means "load" but without knowing "load current" or "load impedance", that's no help. – user_1818839 May 6 '13 at 20:54

## 1 Answer

The burden voltage of a current meter isn't necessarily measured. A current meter essentially measures the voltage buildup due to a current through a known resistor. It is the voltage drop over the multimeter when measuring current.

The (shunt) resistor in the current meter is a know and static value, so if you know what current flows through it, you can calculate the burden voltage by applying Ohm's Law

The burden voltage in that case is $U_{burden} = I_{measured} × R_{shunt}$

• This was mentioned in an EEVBlog video and I didn't get it. Now I understand it, +1. – BSEE May 6 '13 at 23:30