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