Symmetric reference potential

The EL3356 measures the two voltages Usupply und Ubridge independently of each other and without electrical reference to a supply voltage. The measuring accuracy can be increased further, if an internal coupling is employed to prevent the internal measuring circuits from drifting apart. To this end the EL3356 has an internal switch that is closed in the default state and establishes a potential reference between the internal electronics and the bridge point.

Symmetric reference potential 1:
Internal switch for increasing the measuring accuracy

If several strain gauges are supplied by the same power supply and equalizing currents flow that falsify the measurement, the switch can be opened via CoE 0x8000:05. Alternatively, electrically isolated strain gauge supplies are to be installed.