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TARE WEIGHT
: (DATA line 2)
In DATA line 2, tear weights should be consistently within a few grams of each other from cycle to cycle. Large variations in
the tare weight numbers may indicate excessive vibration, some mechanical interference with the weigh bin, or a faulty
circuit board. Tare weights above or below zero are not a problem as long as they are consistently similar from cycle to
cycle. When problems are present, tare numbers may vary by up to 50 grams. Variations of 2 or 3 grams are not a
problem.
RETRIES
: (DATA line 3 and 1, FIRST and FINAL dispense)
When FIRST time dispense, (DATA line 3), does not equal FINAL dispense, (DATA line 1), one or more retries have
occurred. Retries are evidence of a problem that will also cause percentage errors.
Retries may indicate possible problems; perhaps the hopper ran out of material, or the flow rate is so erratic that the first
dispense was short for no good reason. Parameters _RT and _RP determine what shortage error is necessary to force a
retry.
FLOW RATE NUMBERS
: (DATA line 2)
Check the RATE numbers, (DATA line 2), to determine each dispense device.
In the example above:
In the component 1 column, 18224 and 976 translates to 1822.4 grams in 4 seconds (244 interrupts = 1 sec). This is 455.6
grams per second, typical for a regrind flowing through 3" round or 2"x3" dispense valves.
In the component 2 column, 19993 and 488 indicate 1999.3 grams in 2 seconds, or 999.6 grams per second flow rate. This
is a heavy natural material, not polyethylene. Perhaps Lexan or a glass filled material.
In the component 3 column, 12973 and 31232 indicate 1297.3 grams per 31232 interrupts, or 128 seconds, for a flow rate of
9.99 grams per second. This is a 1” auger feeder, from which we would typically expect about 8 grams per second. More
recent auger feeders use faster motors delivering about 16 grams per second.
In the component 4 column, 10240 and 31232 indicate a flow rate of 8 grams per second EXACTLY. Since it is exact, and
since these two numbers are, in fact, the "default" settings from when the blender was first installed, we know that
"component 4" has never been run on this blender, or at least not since the last "CLEAR ALL" was performed.
DATA line 3 dispense weight of 0.0 for component 4, and the TOP-OF-PAGE heading showing component 4 set to 00.0
percent also confirm that component 4 is not being run.
The following information will help you determine what devices are in place on a blender.
Material Dispense Device:
Approx. Grams per
Second:
½” Auger Feeders, Micro Pulse Valves
0.5 - 02
1” Auger Feeders
06 - 10
Vertical Valves
20 - 40
WSB 100 - Slide Gates
250 - 450
WSB 220, 420 - 3” Round Slide Gates
500 - 900
WSB 240, 260, 440, 460, 940, 960, 1840, 1860 - 2” x 3” Slide Gates
500 - 900
WSB 240, 260, 440, 460, 940, 960, 1840, 1860 - 3” x 6” Slide Gates
3000 - 5000
Regrinds are always lower then naturals. Bulk density will also cause wide variations in flow rates.
ERROR CORRECTIONS: RATE NUMBERS:
(DATA line 2)
The RATE numbers are used by the software, each cycle, to calculate material dispense times. They are adjusted every
cycle until flow rates stabilize. When a significant error is detected, the software adjusts the RATE numbers.
The GRAM number is adjusted first. The TIME number (interrupts) is changed only if the GRAM number goes below 16,000
or above 32,000 (approximately). In this event both GRAM and TIME numbers are doubled or halved to bring the GRAM
number back to between 16,000 and 32,000.
This serves to keep all numbers as large as possible allowing for the most accurate math, but not so large as to overflow the
registers.