transaction log

I think you need a 3rd party tool. Check ours sponsors.

You will not get anywhere using any third party tool or monitoring transaction log, you have to go thru the architecture of transaction log and number of processes (SELECT/INSERT/DELETE/UPDATE) on the server.
Here is what referred in Books ONline:
Every SQL Server database has a log that records all the transactions and database modifications made by each transaction. The transaction log is a critical component of any database, and understanding and managing this log is a critical part of the database administrator's role. This is particularly true under the full and bulk-logged recovery models, which require backing up the log on a regular basis.
TO manage the Tlog:
You can monitor log space use by using DBCC SQLPERF (LOGSPACE). This command returns information about the amount of log space currently used and indicates when the transaction log is in need of truncation. For more information, see /msdn.microsoft.com/mshelp" />DBCC SQLPERF (Transact-SQL). For information about the current size of a log file, its maximum size, and the autogrow option for the file, you can also use the size, max_size, and growth columns for that log file in sys.database_files. For more information, see sys.database_files (Transact-SQL). For more information see Books online.