2 Time Machines, One Computer

I have a mid 2010 iMac with a 1TB internal HD. I have two external HDs. One is a 3TB partitioned into 3 1TB drives. The other external is a 4TB, partitioned into 4 1TB drives.

I've had my internal HD backed up using Time Machine to one of my partitions on the 3TB external HD. Now I want to create a Time Machine on one of the partitions on the 4TB to back up a second storage partition on the 3TB external.

Is it possible to have 2 Time Machines backing up two different HDs attached to one computer?

I hope I've made myself clear. Thx.

Jeff