$\begin{array}{1 1} \text{input voltage cannot be AC voltage , but a DC voltage } \\ \text{maximum input voltage is 220 v} \\ \text{the meter reads not v but } < v^2> \text{and is calibrated to read } \sqrt {< v^2 >} \\ \text{the pointer of the meter is stuck by some mechanical defect } \end{array} $
