Possible Duplicate:

How can I calculate power consumption of my PC in Watt?

I need to investigate how much power my Linux machine uses per week. I can take a look at the PSU but I would like to know how to calculate the average use of power it takes.

I also need to know how much power a CRT screen use per week.

Do I need to check the PSU Watt unit and Screen Watt usage and just add both to have the results?

P.S. My question is not related to: How to choose a UPS / calculate power for a new PC