Voltmeter HB8145

[roloenni]

I have a digital voltmeter HB8145.
Supply voltage on the circuit board says 5v.
On the paper box the supply voltage is marked 5-15 VDC?
Can I use this voltmeter in self supplying configuration for voltages between 10 and 15 Volts or do I need a 5 volt supply voltage?
Is it possible to calibrate the voltmeter with the blue potentiometer in the corner?

Sincerely Rolf

[Tech_Marco]

If there is a label for 6~15V, feel safe to power it by 12V and common ground is ok for our volt meter