What are the TA and CH buffers?

Texas Splash

Mod Squad
LifeTime Supporter
TFP Expert
Test kits have TA and CH buffers which you add before titrating. What are these and what do they do?
R-0010 is calcium buffer, a strong base which prevents interference from magnesium.
R-0007 is thiosulfate, used to neutralize chlorine so it won't interfere with the test. Extra R-0007 can be added when the FC level is very high to help prevent the dye from bleaching out.