Case IH AXIAL-FLOW 2577 Operator's Manual page 144

NOTE: Under normal operation, the meter needle
can move up the scale for a short time before
returning to the middle position. A correction in
ground speed does not have to be made unless the
meter needle stays in the up scale position. If this
needle deflection occurs frequently:
Grain Scan Monitor is set too SENSITIVE
Check the grain loss behind the Combine
Check the Combine and the monitor for possible
problems.
5 - OPERATING INSTRUCTIONS
The grain scan monitor will operate in the ground
speed mode whenever the ground speed is greater
than 1/2 MPH (0.8 km/h). In this mode the readings
are independent of the ground speed and are based
on seed loss per area.
The grain scan monitor will operate in the time based
mode whenever the ground speed is less than 1/2
MPH (0.8 km/h) or when the Combine is stopped.
This mode is used primarily to check stationary
sensor operation, but will show time based loss rates
at very slow speeds.
NOTE: If there is a sudden change in Ground Speed
(needle UP if you slow down - needle DOWN if
you increase ground speed), the monitor will
stabilize to normal operation in approximately 90
seconds.
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