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© Sealevel Systems, Inc.
SeaI/O | SL9049 11/2021
Ground-Referenced Signal Sources
A ground-referenced signal is a signal that is connected in some fashion to the building system ground
and therefore is already connected to a common ground point with respect to the SeaI/O-570. Examples
would be non-isolated outputs of instruments and devices that are connected to the same building power
system as the SeaI/O-570. The difference in ground potential between two devices connected to the
same building power system is typically 1mV to 100mV and can be much higher with improper power
system grounding. This ground potential difference can show up as a measurement error without using
the proper measurement connections. The above connection scheme is designed to eliminate this
ground potential difference from the measurement.