This page describes the operation of a proof
test system for verifying the proof load of rope, wire rope, web
slings and other forms of rigging.
A multi-range load cell is used to measure the
force during the operation of the test system. The MONITOR displays
the force in pounds.
The A2D Convertor is attached to one of the computer's
standard serial ports. The monitoring portion of the system uses
a Microsoft XP software and Roberts Proof Test Certificate software
package for load data acquisition, display, and the printing of a
test certificate. The following diagram illustrates this type of
system:
During
a test, the system continually monitors the load, captures the peak
load, and displays the data. Once a test has been completed, the
operator can easily print a test certificate containing all pertinent
data and a plot of the test load vs. time.
A2D Convertor
With the A2D Convertor, reading test results
is simple and easy. The monitor displays pounds of force in a single,
clearly visible window, eliminating the time consuming task of gauge
interpolation.
An excellent feature of this A2D Convertor is
its separate peak/hold range. It resets automatically, assuring the
peak of the last test is retained.
Load cells and gauges are normally calibrated
for only 10% to 100% of their range. The lower 10% of a range is
usually neglected. With the Auto Range function, calibrating at the
lower limits is possible. The A2D Convertor automatically selects
between two ranges and allows the operator to test at lower levels
of force. The standard is 1% to 100% of the maximum range.
An RS232 output plug will be needed for connecting
a computer. If a computer is not wanted at this time, the RS232 output
plug is a very inexpensive way to plan for the future.
General Description of Software
This A2D Convertor is compatible with Roberts
Proof Test Certificate Software. This software program prints a computer
generated Test Certificate from the load indicator of the actual
load on the test machine. An RS232 output plug is required for connecting
the computer to the digital indicator.
Automatically Collects Test Data
Data available for recall
Saves time and reduces errors
Computer Hardware
It is preferable for the customer to buy their
own computer hardware. However, if desired, Roberts Testing Equipment,
Inc. will furnish the computer hardware and software as a package.
Necessary hardware:
Computer with Microsoft XP and a printer.
RS232 output plug is required for adding the
computer
A2D Convertor
Automatic Set-up, Calibration and Scaling with
Sensor
1 to 14 Channels
Full 6 Digit Display (999,999)
16 Bit Resolution
Field Selectable Self-calibration:
Shunt-Cal, MV/V, or Known Load
Full Featured
RS-232 or RS-485 Interface
The Model A2D Converotr is a self-calibrated
analog to digital convertor. When used with Signature Calibrated
transducers, the Model A2D will self-calibrate span, decimal point,
and engineering units automatically and periodically. An auto-zero
circuit will zero the indicator when no load or pressure is applied
to the transducer.
The A2D is capable of using the transducer's
mV/V calibration information to calibrate itself to nearly any transducer,
including amplified voltage- or current-output cells. This allows
for four field-selectable methods of self calibration, including
Shunt cal, mV/V, and 2- and 3- point known load calibration. The
transducer's output-versus-load characteristics including linearity
data, are stored within the Model A2D, and produce an accurate display
and digital output.
Additionally, the Model A2D provides a selectable
0-5V, +/-5VDC, 0-10 VDC, or an optional 4-20 milliampere analog output
from each channel with filtered frequency response. The Fast Peak
feature (SC200 only) is a true analog detector, thus providing a
rapid 1 millisecond response, yet exhibiting no bleed-off. Tare is
push button or remotely activated.
RS-232 or RS-485 digital communication provides
for control and readout of the instrument remotely at up to 9600
baud.
