YSI WaterLog Series, Owner'S Manual

Page: 46 / 174

AC-In
The AC-In frequency input is found near the beginning of the bottom row of ports, next to the
Digital ground port (Dgnd), on the front panel of the System 5000
. A sensor will typically
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connect to at least the ACIn and Dgnd ports.
The AC-In frequency input is normally used for wind speed sensors but can be used with any
sensor that produces a low level AC frequency output. The AC signal is normally in the range of
0.15 volts peak to peak centered at 0.00 volts. Though the Digital I/O ports also support
frequency readings, only the AC-In can accurately measure low level frequencies.
Frequency readings typically take a few seconds to accurately measure. To add a Slope or Offset
to the measured value, use Math & Data Options.
5-2 Inputs
System 5000
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