Tobasco uses a process called "lactic acid fermentation". This used the natural bacteria on the peppers along with the salt brine to ferment the peppers. When the are fully fermented, they add the vineger and you end up with a product with a virtually endless shelf life. If you search on the forum or one the harvest forum there are some quite interesting threads on fermentation and hot sauces and a few people that are actively doing it.
As far as links go, I am at work and cannot look for one now, but google "lactic acid fermentation" or search on here for the thread about the process.

As far as ph meters go, you have to buy a ph meter. I bought mine at ebay for about 30 dollars. It includes two solutions for calibration and full directions.

kendra

Kendra,

Thanks for the ebay headsup! I have one exactly like this and is the one I use for sauce because has perfect probe end. Incredible price too.

jt

Here is a link that might be useful: pH meter