TM 5-3895-374-10
............................................................................................................................................... Description of USER OPTIONS
Lines 1 and 2 define options applied to the aggregate scale conveyors. The alternative options are "measured by scale" or
"measured by volume". The preferred mode, and possibly the only mode allowed by the governing quality control agency,
is "by scale". This mode proportions the liquid A/C according to the weighed aggregate rate as measured by the aggregate
scale. If the scale becomes inoperative, and if the operator is confident that the volumetric feeder calibrations are
accurate, and if the operator is certain that these feeders are reliable and consistent in operation he may elect to ignore the
scale and proportion the A/C according to the "aggregate measured by volume". Even in the "by volume" mode, the
computer keeps track of the exact time sequence of events. The only difference in the entire process control is that instead
of measuring a scale value the computer calculates and uses the desired target aggregate value that corresponds in time
with the actual aggregate crossing the weigh scale.
NOTE:
Do not use this backup mode of operation unless you fully understand the factors that can affect mix
quality when proportioned volumetrically.
Line 3 defines the method by which the A/C temperature is acquired. The preferred mode of operation is "A/C temperature
is measured by probe’’. In this mode the A/C temperature is automatically measured and may be used to continuously
temperature compensate the asphalt meter. If the temperature sensing probe or circuitry becomes inoperative the user
should elect to change to "A/C temperature is entered by user" at which point he will be allowed to enter the observed A/C
tank temperature manually on the Material Parameters Display (option (3>).If the asphalt meter is temperature
compensated by the computer, this manually entered value will be used to effect the compensation. In the "entered by
user" mode the A/C temperature display and printout will be shown in parenthesis to show the operator that the value is not
measured but is entered by the user.
Line 4 defines the method by which the total asphalt in the mix is calculated. The most common method is to calculate
such that "A/C blend is a % of total mix. Total mix includes virgin aggregate, recycle, any other additives and the added
A/C. The alternate method of calculation is as "a % of total aqqreqate". Aggregate includes all the components of total mix
except it does NOT include the added A/C. Therefore:
by mix:
%mA/C =
(+A/C)
x 100
Virgin + Rap + Additives + (+A/C)
by agg:
%aA/C =
(+A/C)
x 100
Virgin + Rap + Additives
page F - 102
SYSTEMS Equipment Corp. 8/31/89 Page (54)
