I would like to monitor the power consumption in my home. I know you can measure the current using a current transducer but how would you measure the voltage in a isolated fashion. Is there a device like the current transducer or do I have to connect something directly to the mains to measure the current voltage level.

 

There are inexpensive devices on the market, like the Kill-a-Watt.

If you mean to do your own monitoring, the you must use a transformer to isolate the circuit from the line, and to drop the voltage to some level close to the input limit of the monitoring device.

How are you intending to read the power consumed?

 

Do you not have a meter on the side of your home? Simply read it for whole house consumption and buy a kill-a-watt for individual device usage monitoring.

 

You'll have to be more specific about what you want to do. Usually, we measure things to help us make decisions, so tell us what you want to decide. Measuring things just because you're curious is OK too. Tell us what your budget is and what your skill level is. There are numerous ways to do what you said you want; many of them are not for beginners. By far the cheapest and easiest way is to use your power company's power meter and a Kill-a-Watt meter, as has already been mentioned.