As I am into many other things.
And firmly believe, in, 'cross' purposing things.
( Like, crushed walnut hulls, for cleaning Brass, (Cartridges), can cost, 15.00 for a pound, in a Gun shop, but the Pet Store, under, Lizard Bedding, cost 5.00 for 10 pounds.  Same Thing !)

Anyway, was exploring a new PID Controller for a old lead melting pot.
And came accost this site: http://www.auberins.com/
All Sorts of gadgets and controls.
For someone wanting to experiment, and knows a little wiring.
You could measure just about anything on your M.C.

Especially this gadget: http://www.auberins.com/index.php?main_page=product_info&cPath=5_21&products_...
You can measure: pressure, temperature, battery voltage, air/fuel ratio, all depending on what you 'plug' it into.

Would be fun to experiment with.