TM 5-3895-374-10
......................................................................................................................................................FEEDER information display
-CAUTION REGARDING VOLUMETRIC-RATES-
When rates are determined volumetrically, the calculated blends and the totals the computer derives from these rates are
based on feeder speed in revolutions per minute and on the user specified calibrations relating feeder speed and
material flow. Actual material flow is not measured and rates are therefore accurate only if:
(a) calibrations are accurate at the actual feeder speed
(b) material is in the feed bins and its flow from the feeder is not restricted
(c) the drive train between the motor and the feeder is not slipping (d) the correct material moisture is
entered into the computer.
The %err column for the virgin and recycle scales displays the difference between the measured combined aggregate at
the scale and the target volumetric aggregate request. If the system were perfect and there were no volumetric errors this
%err would be zero. Deviations from zero are therefore deviations from perfect and reflect the uniformity of the materials
and the material delivery system. Conversely, if the displayed Xerr value is relatively constant, it can be expected that the
material delivery system and the resulting aggregate blend is relatively constant.
NOTE:
This Xerror value is often the first indication of problems with the aggregate proportioning system.
This computer system provides a method for the operator to establish alarm limits for the xerr values. When the error
exceeds these limits, the applicable %err value will flash and the ’horn’ will beep. If desired, automatic plant shutdowns
can be connected to respond to persistent errors. For further information see the section on Alarm Limits & Shutdowns.
page F - 15
SYSTEMS Equipment Corp
8/31/89
Page (9)
