[volt-nuts] Thommen Model 230 Multifunction Calibrator

[Victor Silva]

It seems to me this is what is commonly called a process calibrator.  Many 
manufacturers make Process Calibrators, like Fluke for example.
A Process Calibrator is used in manufacturing to typically calibrate field 
sensors and 4-20mA loops, etc.  Most of that equipment can be supported easily 
by a 1% to 0.01% calibrator. So process calibrators are a few orders of 
magnitude less accurate than a typical metrology calibrator.

--Victor