1. I am using digital mutilmeter for measuring voltmeter.
It has 9V battery for multimeter operation.

2. My question is when I use digital multimeter for voltmeter purpose, do black probe of multimeter is shorted to its internal 9V battery or both are isolated?

 

1. I am using digital mutilmeter for measuring voltmeter.
It has 9V battery for multimeter operation.

2. My question is when I use digital multimeter for voltmeter purpose, do black probe of multimeter is shorted to its internal 9V battery or both are isolated?

Why you asking that?
Unless there is an isolated dc to dc inside, otherwise you can say that they are on the equal voltage level and connected together.

 

You can confirm that yourself.If you have another DMM,check continuity between the negative probe and the battery negative terminal.

 

1. I am using digital mutilmeter for measuring voltmeter.
It has 9V battery for multimeter operation.

2. My question is when I use digital multimeter for voltmeter purpose, do black probe of multimeter is shorted to its internal 9V battery or both are isolated?

Depends on the DMM. However, in most cases for example if you try to measure the internal battery of the DMM (DMM measuring its own battery) it will not work. A typical 9 volt battery will measure about 6 volts or so. This is because in most cases the meters A/D (-) Input is raised above the (-)Input of the battery lead. The DMM (-) input and the battery common or (-) are not the same reference point.

Ron

 

Yes, most multimeters do not connect the 9V battery to the common because of the design of the typical IC used for the A/D conversion which cannot measure down to the negative battery rail.

You can however, determine the multimeter's battery voltage by measuring the voltage at both the plus and minus battery terminal using the plus lead (leaving the minus lead disconnected) and adding their absolute values together.