Milestone-Proposal:Weston Meters

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Docket #:2013-31

This Proposal has been approved, and is now a Milestone

To the proposer’s knowledge, is this achievement subject to litigation?

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

Is the achievement you are proposing within IEEE’s designated fields as defined by IEEE Bylaw I-104.11, namely: Engineering, Computer Sciences and Information Technology, Physical Sciences, Biological and Medical Sciences, Mathematics, Technical Communications, Education, Management, and Law and Policy. 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 IEEE Milestone? Yes

Year or range of years in which the achievement occurred:


Title of the proposed milestone:

Weston Meters, 1887-1893

Plaque citation summarizing the achievement and its significance:

Edward Weston and the Weston Electrical Instrument Company introduced the first portable and direct-reading current and voltage meters in 1888-1893. Weston inventions enabling this were the first truly permanent magnets, temperature-insensitive conductors, low-resistance and non-magnetic springs, metal coil frames where induced eddy currents provided pointer damping (1887), and the electric shunt (1893) for the measurement of large currents and multiple current ranges in a single meter.

200-250 word abstract describing the significance of the technical achievement being proposed, the person(s) involved, historical context, humanitarian and social impact, as well as any possible controversies the advocate might need to review.

IEEE technical societies and technical councils within whose fields of interest the Milestone proposal resides.

In what IEEE section(s) does it reside?

North Jersey Section

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

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

Unit: North New Jersey Section
Senior Officer Name: Russell Pepe, Chair

IEEE Organizational Unit(s) arranging the dedication ceremony:

Unit: North New Jersey Section
Senior Officer Name: Adriaan J. de Lind van Wijngaarden, Chair

Unit: North New Jersey Section
Senior Officer Name: Russell Pepe, Junior Past Chair

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

IEEE Section: North New Jersey Section
IEEE Section Chair name: Adriaan J. de Lind van Wijngaarden

Milestone proposer(s):

Proposer name: David Has
Proposer email: Proposer's email masked to public

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 in decimal form of the intended milestone plaque site(s):

141 Warren Street, Newark, NJ 07102 L attitude, Longitude 40.741209, -74.178732 N40° 44.4725', W074° 10.7239'

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. The intended site is the Electrical and Computer Engineering Building on the campus of New Jersey Institute of Technology. The original factory and buildings are no longer standing. However, Weston's laboratory where the meters were developed and manufactured until the plant was built in 1903 were on High Street less than one mile from the proposed site. High Street has since been renamed Dr. Martin Luther King Jr. Blvd and borders the NJIT campus. Edward Weston was also a founder of NJIT and left his instrument collection and papers to the University. There is a museum to his contributions in the university Library. The ECE building, where the plaque is to be located has a display of some of the earliest instruments, several of which date to the 1800s.

The factory, built in 1903 was just under 3 miles from the proposed location.

Are the original buildings extant?

No. The company was initially in Edward Weston's Lab at 645 High Street. This building was torn down in the 1960s. In 1903 the company moved to Frelinghuysen Avenue at the corner of Haynes Avenue. This building also has been removed.

A Newark newspaper article in the Newark public library references the destruction of the first building. An examination of the 1903 factory location on google earth shows that it is no longer standing.

Details of the plaque mounting:

Inside ground floor Lobby

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

The University buildings are open during normal business hours and any member of the public can enter the building to look at the plaque. The building is locked at night and on weekends. The university police monitor the alarmed areas of the building and this display can be alarmed if it is deemed necessary.

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

New Jersey Institute of Technology

What is the historical significance of the work (its technological, scientific, or social importance)? If personal names are included in citation, include justification here. (see section 6 of Milestone Guidelines)

The late 1800’s was the dawn of the widespread use of electricity. Power companies were establishing themselves and building distribution systems to supply power for industrial and consumer uses. Street lighting using Arc lamps was introduced. The patent wars over the invention of the incandescent light bulb were fought as electric lighting became cost effective and a competitor to gas lighting. This rise required instruments to quantify the electricity. Efficiencies of motors and generators needed to be measured. Supplied voltages and currents needed to be controlled. Delivered power needed to be measured for billing. However, there was no efficient, calibratable and reproducible way to measure these quantities of electricity. Edward Weston invented solutions to all of the outstanding problems and brought the first reliable, repeatable, calibrated and portable instruments to market helping to enable the rapid expansion and acceptance of the use of electricity.

"Thomas Edison started the electric power and light industries in 1879. Electricity was not metered yet, so electrical measurement became vital as a means to buy and sell set amounts of electricity. Furthermore, these new industries each required multiple power generators with accurate voltmeters, ammeters, and wattmeters . The first electronic measurement instruments were difficult to transport, difficult to use and not suited to work in a laboratory" [1].

"Initially he [Edison] started out with a per-lamp rate. This was unsatisfactory so he developed a chemical ampere-hour meter that consisted of a jar holding two zinc plates connected across a shunt in the customer's circuit. Each month the electrodes were weighed and the customer's bill determined from the change in their weight. This meter was inefficient and error-prone. "[2]. For a more complete description of the electrochemical metering of Edison see “Six Years practical experience with the Edison Chemical Meter” [3]

"When measurements of the value of electrical appliances are actually made, the results are often discredited because of doubt as' to the accuracy of the instruments used, and probably the general indifference to accurate work manifested by many electricians may be justly ascribed to the absence of reliable measuring instruments. "[4]

Weston was inspired to start his company after having been hired as a consultant to measure the efficiency of a generator [5]. This took a week to perform which was typical of the time.

By creating a very stable, robust, calibrated and portable instrument Weston solved several key problems of prior meters including: the lack of the ability to calibrate them due to influence of earth’s magnetic field and the lack of permanent magnets, the sensitivity to resistive heating during measurement, the lack of accuracy and repeatability, and the complexity of making measurements. These meters became the standard of measurement internationally [6] aiding in the rapid spread and acceptance of the use of electricity.

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

There were a variety of measurement instruments available at the time. Perhaps most importantly, none of them could be accurately calibrated. [4] All instruments of the time that used permanent magnets suffered from the decay over time of these magnets making the instruments fundamentally unable to be calibrated [7]. Instruments using electromagnets also could not be calibrated because of the hysteresis inherent in the soft magnetic materials [7]. Hence, it was a tedious business to measure a current in milliamps. [7] Existing instruments were also sensitive to variations in the earth’s magnetic field and hence required instantaneous measurements of the earth’s field at the same time as reading the meter. They tended to be very delicate. Those with suspended coils had to be leveled while those with lamps required careful set up and alignment.

Additional difficulties faced by all instruments to some degree included [4], [7]: Instability of readings because of resistive heating of the coils during measurement causing changes in the resistivity of the coil and hence in the meter readings, insufficient damping of the indicators, restoring springs were made of steel and interfered with the magnetic circuit stability as well as providing too high a resistance. [8]

Meters tended to overheat if left in the circuit for long enough to take a reading [9] and the changing resistivity with temperature of the coils further aggravated the measurement difficulties. This was believed to be an inherent problem as the Physics community of the time believed that positive temperature coefficient of resistance was one of the defining features of a metal. [8]

Meters measured either small or large currents but all had a limited range. Large voltages required a large resistor in series with the meter, however all resistors also had substantial temperature coefficients of resistance so that the act of making the measurement affected the resistance and altered the reading. Large currents required very thick copper wires leading to the coils and coils with large current carrying capacities.

What features set this work apart from similar achievements?

Edward Weston took a holistic and systematic approach to all of the outstanding issues and solved each of them to create “the first highly accurate, direct-reading, direct current, portable voltmeter. A complete line of devices for both direct current and alternating current soon followed.” [10] Others working in this area managed improvements, but none approached the scope of the improvements incorporated into these meters[11].

These instruments contained the first truly permanent magnets, a prerequisite for meters to be calibrated and given a true scale. The material science included optimizing the iron alloys to hold their magnetization, establishing the magnetization through repeated hysteresis cycles to only about 2/3 of the saturation magnetization, and stabilization with a Weston developed heat treatment. The electrical science involved creating a very nearly complete magnetic circuit with minimal air gap so that the reluctance of the gap created negligible drag on the magnetic fields. Weston accomplished this by using a piece of soft iron on the end of each pole piece that was shaped to match a concentrically mounted soft iron cylinder. The gap between these pieces was where the coil rotated and averaged only .05” in Weston’s instruments. The curvature of these pole pieces ensured that the measuring coil moved in a uniform magnetic field ensuring linearity of the scale. [5]

Weston solved the heating problems of contemporary meters by developing two new metal alloys, Constantin and Manganin. Constantin had a negative temperature coefficient of resistance which defied the currently held belief that a defining property of metals was a positive coefficient. Thermoelectric generation of current at the Constantin-Copper interface determine that Manganin was chosen for the coils. This resulted in stable readings that allowed these to be the first meters that could be left in a circuit for more than a few seconds during measurements. These meters could have direct reading scales calibrated in the factory rather than before each measurement. This invention also improved the measurement of large voltages which required a large series resistance. Manganin was the ideal material for this because of its almost zero temperature coefficient of resistivity. [5]

To eliminate the effect of the magnetic field on the restoring springs, Weston rejected steel springs and developed a non-magnetic alloy of Copper with very low resistance which he used. He used two opposing springs to ensure constant restoring force. To lighten the weight of the moving coil he developed a new Aluminum alloy that allowed it to be drawn into a narrow and hollow pointer. [5] Weston developed a light copper (later Aluminum alloy) frame that his coils were wound around. [5] [11]. A key aspect of winding around a metal frame was that the eddy currents induced in the frame provided optimal damping to the needle. The coils that were simply stiffened with glue would oscillate back and forth across the correct reading.

Finally, in 1893 Weston invented the use of a shunt to allow measurement of large currents and the use of multiple calibrated current scales in a single instrument. Thick costly bars of copper to move current through the coils for measuring large currents were made obsolete by this new technique. The shunts took advantage of the low temperature coefficient of resistance of the manganin alloy developed for the coils.

These instruments were of such precision and accuracy that they were adopted as the standards by nearly every large United States company [12]. They were viewed so favorably in Germany that they were chosen by the Official Testing Committee of the Frankfurt International Electrical Exposition for their work testing all electrical equipment presented at the exposition in 1891. [13] Their importance in Japan is clearly indicated by the title "Weston was the Icon of Meters in Japan" of Dr. Eiju Matsumotos talk at the 2007 IEEE Conference on the History of Electric Power

These achievements are principally documented in US patents 381,305[14], 392,385[15], 392,386[16], 392,387[17], and 496,501[18]

Supporting texts and citations 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 chapters in scholarly books. 'Scholarly' is defined as peer-reviewed, with references, and published. 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. All supporting materials must be in English, or accompanied by an English translation.

[1] E. Matsumoto, "Edward Weston Made His Mark on the History of Mesurement," IEEE Instrumentation & Measurement Magazine, pp. 46-50, 2003.

[2] "Watthourmeter," [Online]. Available: [Accessed 7 February 2014].

[3] W. J. JENKS., "Six Years' Practical Experience WITH THE Edison Electrical Meter," journal of the AIEE, vol. VI, no. 2, pp. 2-45, 1889. File:Six yrs w edison chemical meter AIEE Vol 6 1888-1889.pdf

[4] "THe New Weston Voltmeter," Science, pp. 97-99, 8 February 1889. Provided Courtesy of JSTOR at or File:Science Mag 1889 on Weston Model 1.pdf

[5] W. E. I. Company, Measuring Invisibles, Weston Electrical Instrument Company, 1938. File:Weston-measuring-invisibles-OCR.pdf

[6] Matsumoto, E., "Weston was the icon of meters in Japan,"2007 IEEE Conference on the History of Electric Power, vol., no., pp.165,170, 3-5 Aug. 2007 File:Matsumoto-Newark.pdf

[7] C. N. Brown, "Edward Weston and His Meter," in Sixteenth I.E.E. Week-End Meeting on the History of Electrical Engineering, 1988. File:C.N.Brown-Weston and his Meter.pdf

[8] D. O. Woodbury, A Measure for Greatness: A Short Biography of Edward Weston, New York, NY: McGraw-Hill Company, 1949.


[10] "National Inventors Hall of Fame," 2014. [Online]. Available:

[11] "THE WESTON DIRECT READING ALTERNATING AND CONTINUOUS CURRENT VOLTMETER.," The Electrical Engineer: A Weekly Review of Theoretical and Applied Electricity , Vol XII, p. 656, 16 Dec 1891. File:The Electrical Engineer vol XII-small.pdf

[12] "Trade Notes," The Electrical Engineer: A Weekly Review of Theoretical and Applied Electricity, Vol XII, p. 292, 9th September 1891. File:The Electrical Engineer vol XII-small.pdf

[13] "The Frankfurt International Electrical Exposition - X," The Electrical Engineer: A Weekly Review of Theoretical and Applied Electricity, Vol XII, pp. 547, 649& 71, 18 Nov 1891. File:The Electrical Engineer vol XII-small.pdf

[14] E. Weston, "Electrical Coil and Conductor". USA Patent 381,305, 17 April 1888. File:Patent US381305.pdf

[15] E. Weston, "Electroplated Coil for Measuring Instruments". USA Patent 392,385, 6 November 1888. File:US392385 Electroplated Coil for Measuring Instruments.pdf

[16] E. Weston, "Electrical Measuring Apparatus". USA Patent 392,386, 6 November 1888. File:US392386 Electrical Measuring Apparatus.pdf

[17] E. Weston, "Electrical Measuring Apparatus". USA Patent 392387, 6 November 1888. File:US392387 Electrical Measuring Apparatus-Voltmeter.pdf

[18] E. Weston, "Shunt for Electrical Measuring-Instruments". USA Patent 496,501, 2 May 1893. File:US496501 Shunt for Electrical Instruments.pdf

[19] Miller, John H., "Electrical Measuring Instruments", Weston Technical Monographs, TM-101, 1956

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.

Notes: Edward Weston was a founder of the Newark Technical School which eventually became NJIT. He served on its board of trustees for its first six years of existence. He left his artifacts and documents to the the school and there is a museum of his artifacts in the University Library.

He was also a founder of the AIEE and president from 1888 to 1889.

Section approval letter (2014)

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." Note that there are multiple texts of the letter depending on whether an IEEE organizational unit other than the section will be paying for the plaque(s).

Please recommend reviewers by emailing their names and email addresses to Please include the docket number and brief title of your proposal in the subject line of all emails.

Sect Chrs Apprvl.doc
Sect Chrs Apprvl.doc