When brining meats using a home made mix you need to be sure that you have the correct % of salts in the fluid. The qty of salt in the water will tell you how long to soak your meats in the brine.
To correctly measure this you will need a Salinometer. A Salinometer is a specially built glass tube with a weight in the end, this tube is sealed which allows it to float in the water. The tube will sit at a certain level in the water and will show you on the indicator that is built into the tube the level of salt you have acheived, which in turn provides you with correct information to determine the time that you need to brine your meats.
Simply fill a tall jug with your brine mix and place the Salinometer into the water and check the reading.
For more detailed information (including charts) on the use of a Salinometer please refer to the Part 2.pdf in the document section of this store.