Dear RRF,
I presume you are seeking additional information to that discussed / accumulated in this earlier thread -
http://www.ifsqn.com...uct/#entry69484
Or perhaps a different context ?
The difficulty with yr current OP is that the queries are potentially of Book Scope for substantial answers. I (and no doubt others) can suggest a few meat haccp books if this helps?
On the other hand, you may get more relevant info. by narrowing yr OP.
Just trying to help minimise loss of hair. 
Rgds / Charles.C
PS @Marrok, it may depend on the situation but usually pH measurement/calibration is relatively straightforward, ie black box level. However to "train" others, it is advantageous if the trainer knows more than the trainees.
If really "challenged", you will need to do some quick learning, eg another textbook, or the net. I can guarantee that otherwise some smart*** will find a trick question.
added - Just noticed yr semi-parallel post -
http://www.ifsqn.com...-to/#entry72844
best to try to avoid multiplication, causes confusion.