EMC is generally divided into two major areas, one is EMI (through the space to emit electromagnetic drive interference with other electrical equipment), the general test items: radiated emissions nuisance, conducted emissions nuisance, low-frequency magnetic field emissions nuisance. Another is EMS (electronic products itself to resist other electronic products issued by the ability to electromagnetic harassment), the general test items: electrostatic discharge, radiated immunity, conducted immunity, low-frequency magnetic field immunity, surge, harmonics, fast pulse group.
Each test item corresponds to the equipment manufacturers are many, according to the test item to determine which equipment manufacturer is better. For example, EMI inside the receiver to be used, the use of more Germany's Rohde & Schwarz. ESD currently look at the special test with relatively more.
EMC equipment to consider the purchase of many factors (cost, scalability, actual demand, etc.), not that others say good use, go buy.