The Supermarket Call us to place an order. Protecting Patients Electrical Equipment Grounding Electrically powered equipments, be they medical instrumentation or devices employed in some other environment, operate by using electrical voltages and currents to represent information. Information is received and passed on by the instrumentation in the form of electrical voltages and currents passed through a point of debarkation called an interface.
Any electrical equipment has a ground reference point.
In many cases this reference point is electrically tied to actual earth ground, by a wire connection to a cold water pipe for example. In other cases some continuous metal surface, usually, the equipment's enclosure, is designated as the reference point and referred to as frame ground, and connected to the AC power ground. The first area of concern is proper representation and interpretation of instrument measurements. If the different instruments are employing different ground references there will immediately be problems of accuracy. Basically, measurements are being made by the two instruments, but using a different reference point.