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What's New in Temperatures
SensorsJanuary 2002 Temperature
SensorNews back copies are archived and accessible through the News
page in the event
you miss one or need to check something you saw months earlier. The first (Preview)
Newsletter was dated September 2001!
You may be receiving an email inviting you to sign up for the e-Newsletter
TemperatureSensorNews. If not, an on-line sign up will be available
shortly; check this page regularly for the announcement. One thing to know, your
email address will always remain confidential. Any email address received for
this site's activities will never be sold. Check our privacy
policy!
Featured New Product
From
Dallas Semiconductor (one of the companies listed on the Semiconductor
Temperature Sensor Vendor page), the Thermochron iButton® is a
revolutionary, tiny, battery-powered (ten year life) temperature (-40°C to
+85°C) measuring and recording device. It incorporates a direct-to-digital
temperature sensor, a Y2K-compliant real-time clock calendar, lithium battery
and nonvolatile memory in a 16mm diameter water-resistant, rugged stainless steel
enclosure. It can be dropped, stepped on, generally mistreated and still continue
to "perform the mission", that is, record its own temperature for years.
It seems ideal for any product that would require a time-temperature history for
safety or quality assurance reasons, such as blood storage, frozed food transport
etc.In quantity, individual devices cost only a few US Dollars apiece.
Because of this unique,
durable package, up-to-date information can travel with a person or object. The
steel button is rugged enough to withstand harsh outdoor environments; it is tough
enough for a person to wear everyday on a digital accessory like a ring, key fob,
wallet, watch, metal card or badge (all of which, incidentally, can be purchased
from the Thermochron site). The Thermochron iButton® integrates
a thermometer, a clock/calendar, a thermal history log, and 512 bytes of additional
memory to store identification information, for example, a shipping manifest.
It has advanced
features including: 2048 time-stamped temperature readings with optional data
wrap and 4096 bits of general-purpose read/write nonvolatile memory. It can be
set up to store reading over a wide range of time scales, seconds to years accurately
to +1 minute per month from 0°C to 45°C . The recyclable iButton logs
data for more than 10 years or up to 1 million temperature measurements.
Information is
transferred between a Thermochron iButton® and a PC with a momentary
contact, at up to 142K bits per second. See "Transmitting
Data and Power over a 1-Wire Bus" (Sensors Magazine Article). One simply
presses the iButton® to the Blue Dot receptor, a $US 15 pipeline into
a PC. The Blue Dot sticks to any convenient spot on the front of the PC and is
connected to the serial or parallel port in the back.Set up and access to stored
data are performed with easy-to-use PC software. 
A
Thermochron iButton® Evaluation Kit costs about $25 including the interface.
The kit includes: one Thermochron iButton®, one Keyring Fob Attachment,
one 9-pin Universal 1-Wire COM Port Adapter, one Blue Dot Receptor with RJ-11
Connector and Instruction Sheet. You can download a demonstration and evaluation
program from the Thermochron
web site (requires an iButton to use). Programmers can also download a Java™
example for the Model DS1921 at: ftp://ftp.dalsemi.com/pub/auto_id/public/iButtonTMEXJava0-02-3.zip
These devices have
been around for a few years and are widely known by several Original Equipment
Manufacturers, such as
Point Six , who ruggedize the unit further or may incorporate it into portable
temperature data loggers like KoolTrac
does. Other non-temperature measuring models are used as data collectors
for such organizations as the US Postal Service. However, it is not all that well
known among individual researchers, students and hobbiests. In addition, the product
line is about to undergo a significant upgrade, according to the manufacturer.
There are many other variants and associated kit products, such as a miniature
weather station kit. Sign
Up for the Thermochron Interest Group
If you have questions and ideas,
visit the website and/or
contact the Thermochron Interest Group, where one can keep up with developments
and swap ideas with other Thermochron users. To sign up, send an e-mail to majordomo@iButton.com
with the words "subscribe Thermochron" in the message body.
NEW Links of Interest -
January 2002 Thermochron
web site, dedicated to the
iButton temperature data logger featured as the product of the month for January
2002.
A J Thermosensors Ltd, West Sussex England ," wherever a temperature
measurement is required, AJT can supply both the sensor and the instrumentation
to suit the application"; Thermocouples; RTDs, and more. Monroe
Infrared Technology Infrared Process Cameras, Security Systems, Software
and Training Programs. Page
Updates New
reference articles added to References page:
A Handbook on Temperature
Measurement in Three Volumes from Springer-NY., Three
classic scientific papers reviewing Cryogenic Thermometery and, A
Review
of Scientific Instruments article from August 2000 available on the Web.
The latter provides a concise summary of almost every type of temperature sensor
imaginable, including some uncommon types used in special studies on gas temperatures
and other research activities. A particular feature of this and the other three
articles is the extensive list of books and journal articles references at the
end of each paper. The very nice thing about these references lists is that they
are placed in context by the reviews.
New Pages
A major new page on Cryogenic
Temperature Sensors and Cryogenics has been added. This is another of the
unique areas of temperature sensor applications. This particular area spans a
wide range of technology, engineering and manufacturing from basic research in
nuclear physics, condensed matter and biotechnology to steel making and food processing.
Cryogenic
Temperature Sensor Vendors A new page of vendors who focus on very low temperature
sensors and those that can measure accurately in the presence of magnetic fields.
Next
Month's Plans Next
month's plan is a set of new pages devoted to thermowells. For those who wish
to periodically remove and/or replace a probe type temperature sensor without
creating a leak in a system or process line, a thermowell is the ideal object.
It stays on, or in, the process and the sensor can be removed and replaced without
concern. This is especially critical where a leak could do more than create a
mess, e.g. a hazardous chemical or gas, a very valuable product, a product under
high or low pressures. Perhaps the point is made. Thermowells are used in processes
ranging from biomedical to petrochemical. There are many sets of measuring conditions
and corrosive situations, yet all require and obtain desired temperature measurement
capability through the use of thermowells. Pretty significant items in many operations
and they are available in quite a wide variation of sizes, shapes, materials and
design. Come and visit next month to see for yourself. Thermowells.
COMMENTS
+ END NOTES We
have had several requests to add some listing for Manufacturer's Reps and Distributors
to this site. It would be limited to those who specialize in temperature sensors
and related products. What do you think? We'd appreciate your feedback.
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