Figure 16.9 shows an example of a measurement system that uses the single-point grounding method. All the ground leads are connected to the system's earth-ground connection at the same point. The best practice is to locate this single ground point closest to the instrument in the system that is most susceptible to the interference (i.e., the point of gain For in Fig. 16.9 would be the point where the amplifier is connected to the system's earth-grounded conductor. By using single-point grounding, conductively coupled interference due to a common-impedance path is also minimized. Note 16.9 that the power supply, amplifier, and digital instruments have their power-line from ground by isolation transformers. These system components are therefore each connected to ground only at the single grounded point of the system.