Metalfab Better-Weigh Feeders - Manual (Page 5)

Better-Weigh _ Feeders
Installation and Operating Instructions
Metalfab, Inc. Vernon, NJ 07462 Phone (973)764-2000 Fax (973)764-0272 [email protected]
5
Both of our instruments use Filtering (vibration
elimination). Think of vibration elimination as “Magic
Numbers”.
In most cases “Magic Numbers” are an asset. But as
with everything else, there is a limit.
We like the fact that the “Magic Numbers” eliminates
repetitive noise, but too much filtering dampens your
readings. When changing the filtering settings, you
sacrifice time. The higher the setting, the longer it takes
to make that filtering calculation.
M EASURING A CCURACY :
When testing one of our Better-Weigh® Feeders, we
catch 30 consecutive one minute samples.
The plus & minus deviation of these samples are
analyzed using 2 Sigma deviation formulas.
When sampling, 65% of the samples will fall within one
standard deviation or (1) Sigma and 95% will fall within
two standard deviations or (2) Sigma. The loss-in-weight
industry has standardized on the 2 Sigma as an
accuracy statement.
CONTROL FEATURES - "BETTER-WEIGH"® BATCH LOSS-OF-WEIGHT FEEDER
With the "BETTER-WEIGH" batch feeder model BWP,
accuracies of =/- 0.5% can be achieved with 2 lb.
batches and +/- 0.25% accuracy with 5 lb. or greater
batches with time spans of 30 to 90 seconds. The BWL
model can easily produce an accuracy of +/- 0. 5% in 1
lb. batches.
The METALFAB batch controller is used to control the
fast (bulk) and slow (dribble) speeds of our
"BETTER-WEIGH"@ feeders.
1. The bulk dribble targets are entered through the
front panel or down loaded to the indicator using
RS-232 or optional RS-485 and Allen Bradley
Blue Hose communications. The feeders fast
and slow speeds are set manually and are
initiated by the weigh indicator's twenty (20)
programmable steps.
2. In addition to the fast and slow speed outputs,
the indicator has two (2) additional outputs
which can be configured for a refill, batch
complete or general alarm conditions.
3. Formatting printing can be done and is activated
by one of the programmable steps or by
pushing the print button located on the front
panel.
4. The indicator is also supplied with four
accumulators and their values printed through
the print functions.
5. Vibration elimination is used to remove motor
and machine noise from the raw digital data
used for weigh indication. It is also an added
benefit when using vibration to assist with
feeding.
6. Both the SCR DC drive and weigh indicator are
mounted in the same NEMA 4 enclosure having
a power on/off switch with light, Jog/Batch and
Abort/Start selector switches.
7. Normally the control is supplied 230/1/60 VAC
As an option, 115/1/60 VAC can be supplied.
For a detailed description of the Batch Control and
installation, calibration and operating instructions,
refer to the schematics and instructions enclosed in
our control enclosure.