Al said:

Frank will use Grey Poupon, BenT will borrow some generic mustard from
the Jollibee but they'll both get the reading......

But in practical terms there is an inverse relationship between quality
and accuracy with this method.  You really ought to do as many
iterations as possible, and you'll find that the darker, more costly
mustard is harder to read at higher values.  Therefore, I feel that
French's yellow poison is the absolute best one to use.

Only the best for our Vanagons!

Chuck Hill