Milestone-Proposal:Self-regulating Trace Heater

To see comments, or add a comment to this discussion, click here.

Docket #:2017-10</div> This is a draft proposal, that has not yet been submitted. To submit this proposal, click on "Edit with form", check the "Submit this proposal for review" box at the bottom, and save the page.

To the proposer’s knowledge, is this achievement subject to litigation? No

Is the achievement you are proposing more than 25 years old? Yes

Is the achievement you are proposing within IEEE’s fields of interest? (e.g. “the theory and practice of electrical, electronics, communications and computer engineering, as well as computer science, the allied branches of engineering and the related arts and sciences” – from the IEEE Constitution) Yes

Did the achievement provide a meaningful benefit for humanity? Yes

Was it of at least regional importance? Yes

Has an IEEE Organizational Unit agreed to pay for the milestone plaque(s)? Yes

Has an IEEE Organizational Unit agreed to arrange the dedication ceremony? Yes

Has the IEEE Section in which the milestone is located agreed to take responsibility for the plaque after it is dedicated? Yes

Has the owner of the site agreed to have it designated as an Electrical Engineering Milestone? Yes

Year or range of years in which the achievement occurred:


Title of the proposed milestone:

Conductive Polymer Self-Regulating Heater 1971-1999 Invention and Raychem Production

Plaque citation summarizing the achievement and its significance:

On this site in 1973 the first commercial production of AutoTrace, a self-regulating heater, was produced by Raychem Corporation. In 2008, the 1 billionth foot of this heater was produced. The self-regulating heater revolutionized the process piping temperature maintenance and made freeze protection of water pipes simple and energy efficient.

In what IEEE section(s) does it reside?

Santa Clara California

IEEE Organizational Unit(s) which have agreed to sponsor the Milestone:

IEEE Organizational Unit(s) paying for milestone plaque(s):

Unit: {{{Unit}}}
Senior Officer Name: Senior officer name masked to public

IEEE Organizational Unit(s) arranging the dedication ceremony:

IEEE section(s) monitoring the plaque(s):

Milestone proposer(s):

Please note: your email address and contact information will be masked on the website for privacy reasons. Only IEEE History Center Staff will be able to view the email address.

Street address(es) and GPS coordinates of the intended milestone plaque site(s):

2555 Bay Road, Redwood City California

Describe briefly the intended site(s) of the milestone plaque(s). The intended site(s) must have a direct connection with the achievement (e.g. where developed, invented, tested, demonstrated, installed, or operated, etc.). A museum where a device or example of the technology is displayed, or the university where the inventor studied, are not, in themselves, sufficient connection for a milestone plaque.

Please give the address(es) of the plaque site(s) (GPS coordinates if you have them). Also please give the details of the mounting, i.e. on the outside of the building, in the ground floor entrance hall, on a plinth on the grounds, etc. If visitors to the plaque site will need to go through security, or make an appointment, please give the contact information visitors will need. Manufacturing Comples still making the product named in the historical site

No other historical markers.

Are the original buildings extant?


Details of the plaque mounting:

To Be determined, multiple plaques probable.

How is the site protected/secured, and in what ways is it accessible to the public?

Who is the present owner of the site(s)?


What is the historical significance of the work (its technological, scientific, or social importance)?

The idea of conductive polymers was in its infancy and researchers at Raychem looked at silicones and polyolefins as a possible matrix with carbon black infused into the matrix for conductivity. Radiation chemistry was critical to the repeatability of the heating cooling system as shown in the IEEE paper in this package. The circuit was elegant, parallel wires with a positive temperature coefficient matrix between the wires. As the temperature increased, the local resistance increased lowering the heat generation at that specific location. What you had was basically a distributed temperature sensor controlling each section of the heater independently. The product was also cut to length in the field. The solution in 1971 for heating pipes was MI Cable which was manufactured to a specific length in a factory. As one would expect, the field as built piping was never quite the drawing estimates and returns for a different length were common.

What obstacles (technical, political, geographic) needed to be overcome?

Conductive polymer PTC (Positive Temperature Coefficient) tests were made by loading polymers with conductive elements, usually metal powders or carbon black. The resistance change was one way, the resistance went up and never came back. This was solved by radiation crosslinking the polymer which "pulled" the polymer back to the original shape when the temperature decreased. Radiation crosslinking was the secrete.

What features set this work apart from similar achievements?

No conductive polymer had ever been able to cycle to different temperatures and return to its original resistance.

References to establish the dates, location, and importance of the achievement: Minimum of five (5), but as many as needed to support the milestone, such as patents, contemporary newspaper articles, journal articles, or citations to pages in scholarly books. You must supply the texts or excerpts themselves, not just the references. At least one of the references must be from a scholarly book or journal article.

IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL. IA-9, NO. 4, JULY/AUGUST 1973 Some Aspects of a Self-Limiting Resistive Electric Heating Element JOSEPH A. OAKES AND CHET L. SANDBERG

US 3861029 AutoTrace Patent

IEEE 515 Standard for the Testing, Design, Installation, and Maintenance of Electrical Resistance Heat Tracing for Industrial Applications 1997

TYCO THERMAL CONTROLS CELEBRATES AN INDUSTRY FIRST - One Billion Feet of Raychem Self-Regulating Heat-Tracing Cable Manufactured and Sold March 14, 2008

1972 AutoTrace brochure 72

Supporting materials (supported formats: GIF, JPEG, PNG, PDF, DOC): All supporting materials must be in English, or if not in English, accompanied by an English translation. You must supply the texts or excerpts themselves, not just the references. For documents that are copyright-encumbered, or which you do not have rights to post, email the documents themselves to Please see the Milestone Program Guidelines for more information.

Many Available

Please email a jpeg or PDF a letter in English, or with English translation, from the site owner(s) giving permission to place IEEE milestone plaque on the property, and a letter (or forwarded email) from the appropriate Section Chair supporting the Milestone application to with the subject line "Attention: Milestone Administrator"