It's just the I do own a Salinometer and using one makes thing a little easier if you know what readings people have tried and tested.
Brine recipes have a wide range of salt concentrations. But when using a salinometer, keep in mind that it doesn't just measure the amount of salt in a recipe. Other dissolved ingredients such as sugar or molasses will also produce a higher reading, and some brine ingredients such as soy or teriyaki sauce contain salt as part of their ingredients. When using a salinometer, you may get a more accurate measure of the amount of salt in a brine recipe if you test only the water and salt portions of a recipe before adding the other ingredients. You may be able to determine the amount of salt in a cup of soy sauce or teriyaki sauce by using the nutrition chart on the bottle.
A disadvantage of using a salinometer is that it is a time-consuming trial-and-error process. Let's say you want to prepare three cups of a brine with a concentration of 40 degrees Sal. You add a bunch of salt to the water, stir it until it dissolves, which may take quite a while, and measure the salinity. Then you have to add more salt and go through the process again until you get close to the desired salinity. It's faster to dissolve a lot of salt in the water to produce a brine which is more concentrated than you're going to want, and then add water until the concentration comes down to the level you want.
If you want to produce a brine with a specific concentration, or you want to determine the salt concentration in a recipe, it's a lot easier, faster, and more accurate to use a brine table. All it takes is a little math and measurement conversion (how many cups are there in a gallon? How many ounces or grams in a cup of a specific kind of salt?).
Another issue when using a salinometer is that the brine needs to be deep enough to float the salinometer. If you're making two gallons of brine, that won't be a problem. But if you're making four cups of brine, you may need to mix it in a high narrow container so the salinometer will be able to float.
