Xylem H-335 - Manual (Page 8)

1-4 Introduction H-335
Figure 1 Gate Geometry
UserAngle = (SensorAngle UserSlope) - UserOffset ×
1.4.2 User Angle
The UserAngle is the angle, in degrees, thru which the gate has moved relative to the closed position. All
other calculations are based on this measurement. Some dams have a spillway which slopes rapidly
downward from the point where the gate contacts the sill. For these structures, the water flow calculation is
a complex geometric problem because the actual weir opening (distance between the gate and the spillway)
changes as the vertical point from the bottom of the gate first moves upward, then down the incline of the
spillway. For complex gate geometries, program your data logger to record the UserAngle and do the
necessary calculations during post-processing of the data. The UserAngle parameter is calculated internally
in the H-335 using the following equation:
The UserSlope is a constant set to either +1.0 or -1.0 and must be programmed into the H-335 at
installation (see Section 1.8). The UserOffset value is automatically calculated when the extended “aXZO”
command is issued after the installation is completed.