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This is only a preview of the November 2000 issue of Silicon Chip. You can view 38 of the 96 pages in the full issue, including the advertisments. For full access, purchase the issue for $10.00 or subscribe for access to the latest issues. Items relevant to "Santa & Rudolph Christmas Lights Display":
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Articles in this series:
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ShockLog
monitoring the things
that go bump!
Want to know when and where a valuable
shipment was damaged in transit? This
gadget rides shotgun with your goods and can
indicate whether the damage was due to poor
packaging, rough handling or inappropriate
transport methods.
D
AMAGE PREVENTION special
ists Shockwatch Pty Ltd have
unveiled their latest weapon in the
fight against poor product handling
– a “black box” (well, blue actually)
which quietly sits and logs shocks and
vibrations on an object for periods of
one year or more. Called “ShockLog”
it is a compact “tri-axial monitoring
system” which can be unobtrusively
attached to items in transit or storage
to record bumps, vibration and climatic changes.
Designed to be fitted to vehicles,
10 Silicon Chip
containers or delicate valuable equipment, ShockLog has three piezoelectric accelerometers and a temperature
sensor. These sensors, along with
some low-power electronic circuitry,
are housed in an extruded aluminium
case which is bolted to the object it
is monitoring. An additional sensor
can be attached to record humidity,
pressure (as in air pressure) and temperature, if required (this is known as
an HPT sensor).
Shockwatch’s Jeremy Scott says
the ShockLog is effectively a “spy
in a box” to aid the safe transport of
valuable, hazardous or fragile goods.
It can also be used as an aid to designing cost-effective packaging and
for testing different transport methods
and routes.
For example, you can put a Shock
Log inside different types of packaging, send them on a trial journey and
then examine the event graphs when
the consignments are received. That
way, ShockLog makes it easier to develop the right packaging for the job.
Similarly, you could use a ShockLog monitor in several identical consignments sent by different transport
methods to identify which is the best
one to use.
ShockLog is also an ideal diagnostic
tool for the future development of
low-cost, stick-on “damage indicating labels”, which change colour to
indicate when a product is roughly
handled.
ShockLog is already being used
The optional HPT sensor is attached
to one end of the ShockLog and is
used for recording humidity, air
pressure and external temperature.
by the container industry in Europe
and the United States to monitor the
movement of critical cargos, such as
hazardous chemicals and nuclear
fuel. Other ShockLog users include
museums, art galleries, laboratories,
a major guided-missile manufacturer,
optical equipment manufacturers and
Rolls Royce Engine.
Fig.1: the ShockLog is programmed by attaching it to the serial port of a PC and
running the software. This is the setup screen which, among other things, allows
you to program the starting date and time, the “wake-up” threshold, the run
time, the acceleration range and the parameters to be recorded.
How it works?
ShockLog is powered by a single
1.5V alkaline or lithium C-cell battery and can be user preprogrammed
to monitor a range of conditions. It
then records a summary of the data
recorded over a specified time period in its non-volatile memory – you
can set this from 10 minutes up to 24
hours. ShockLog can record a maxi
mum of 512 “summaries”, so you have
to choose a summary period that will
allow you to cover the full period for
which you wish to record.
If preset handling limits are exceeded, the user will be given a visual
warning via a LED. This “time-triggered” mode is designed to monitor
complete journeys. The peak “G” records in each axis are recorded across
any defined “time slot”, along with the
other parameters such as temperature,
humidity and pressure.
To conserve battery life, the unit
normally operates in “sleep” mode.
Then, if suddenly exposed to conditions which exceed a specified “wake
up” threshold (eg, if the unit it is attached to is dropped), the sensor will
activate itself within 1.5 microseconds
and begin recording the incident. By
using the sleep mode, the unit can
maintain a 500-day battery life.
Once activated, ShockLog can
Fig.2: the setup can be saved to disk as
a file and loaded back in at a later date for downloading to the ShockLog. This
feature allows a number of predefined setups to be stored and quickly recalled.
record up to 4000 samples/second
and the 2MB memory is sufficient
for detailed records of up to 400 significant events. It can handle up to
±250G acceleration and is designed
to function in difficult environments,
operating at temperatures between
-40°C and 85°C.
Programming
Programming the ShockLog is easy.
It connects to the serial port of a PC
(75MHz Pentium or better) via a supplied serial cable and works with Windows-based software that’s installed
from an accompanying CD ROM.
This software allows the operator to
program such things as the starting
date and time, alarm thresholds from
1G to 100G, summary intervals, the
recording length of each event (up to
32K), the parameters to be recorded,
November 2000 11
Fig.3: after downloading data from the ShockLog, the “Examine
Data” window shows the recording sessions, the number of events
and alarms during each session and a host of other data.
Fig.4: double-clicking a session in Fig.3 brings up cascading “Event
data” windows – one for each recorded event. You can view the
data in graphical form as shown here or, by clicking the Data
button, display it in data format as shown below.
Fig.5: the data format shows acceleration figures for each axis (in
this case, X, Y & Z). The data can be printed out and exported to
other applications such as Microsoft Excel.
12 Silicon Chip
The ShockLog is supplied in a large plastic carry
case, complete with software and a serial cable.
the total run time and the maximum number of
events to be recorded.
Once the setup is completed on screen, it is
simply saved to disk and downloaded to the
ShockLog unit. The save to disk feature is particularly handy, as it allows a number of prede
fined setups to be stored on the hard disk. These
setups can then be loaded to the setup screen
and downloaded to the ShockLog with just a few
mouse clicks.
Naturally, the software also allows the recorded
data to be downloaded to the PC, saved to disk
and displayed in text or graphical form. These
reports and graphs may be viewed on-screen,
printed out or exported to other applications
such as MS Excel or Matlab.
The software also features a single-screen report that allows all key data for a journey or test
to be viewed, stored or emailed as a single sheet.
Tamperproof
Because ShockLog has no external switches,
it is virtually tamperproof. In addition, all data
is stored in non-volatile flash memory, ensuring
that information can’t be erased without password
authorisation.
It’s use greatly reduces the risk of damage to
valuable shipments by providing users with a
complete record of an item’s handling and shipping history.
For further information on ShockLog and a
range of related products, contact Jeremy Scott
at Shockwatch Pty Ltd on (07) 5534 3811; fax
(07) 5534 3822; email jeremys<at>onthenet.com.au
Shockwatch markets a broad range of solutions
for product damage prevention and industrial
safety. It is an arm of the Dallas-based Shockwatch Corporation in the USA, which has sold
more than 100 million products during the last 15
years for monitoring impact, tilt and temperature
events in product shipments. You can check out
SC
their website at www.shockwatch.com
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