There are three fixed voltage ranges: ± 0 to 200 millivolts DC, ± 0 to 2 volts DC, ± 0 to 20 volts DC. The end user connects a meter utilizing the desired input voltage and reads the voltage directly on the display. Readings in both the positive and negative direction are possible. These meters are ideally used with fixed voltage inputs where no adjustments or scaling is necessary.