ecorder is the adjustable alarm contact which will ound a warning if any of the temperatures being ecorded reaches a dangerous value.

The potentiometer indicators and recorders for se with thermocouple detectors are equipped with utomatic cold junction compensators. The cold unction is taken care of entirely automatically and he user need not bother about the temperature of ne cold junction.

I think that describes about all that we have been oing.

I submitted to the Chairman of your Cable Reearch Subcommittee some notes referring to some f the difficulties which some of the member comanies have experienced when using thermocouples, nd perhaps a number of you have received copies f those notes.

There was some trouble caused by thermocouple ead wire going bad and the trouble was brought to he attention of the company furnishing the wire. The trouble was due to defective insulation; no ruber had been used between the two conductors. I elieve that the company in question is now furnishng rubber-covered wire. All of the wire which we ave furnished has been rubber covered and has iven no trouble due to defective insulation.

We have made a number of tests to determine he effect of high temperatures along the thermoouple leads; that is, higher temperatures than those xisting at the hot junction. In no case did we find ny appreciable error. However, these tests were ade on carefully selected wire and it may be well o point out that thermocouple wire must be carelly selected. Any constantan or advance wire will ot do. If you want to assume a standard calibraon curve for the constantan wire you have to careully select and check the material from the time the gots are cast until the finished wire is drawn to the esired size. We have that very well systematized, nd I believe that some of the other companies also ave adopted specifications for thermocouple wire. One other difficulty has come up in connection ith the checking of thermocouples. I am not sure, ut I believe that some of the peculiar results obined on the cable splice to which Prof. Scott reerred may have been due to errors in checking the ermocouples used, rather than to actual differences temperature. A thermocouple made up of a pair f small wires is a very rapid temperature detector, most instantaneous. In checking such thermoouples the usual practice is to use a well-stirred oilath, but we have found that an oil-bath which is atisfactory for measuring temperatures to within few hundredths of a degree when using resistance ermometers or mercury thermometers (both havg an appreciable time lag) is unsatisfactory for accuracy of one degree when using small thermouples. The difficulty is probably due to eddy curents of oil at temperatures different from the avertemperature of the bath. I think that a simple one avoid errors when checking small thermoAs s is to place the couple and the standard being ted very close together and to fasten both couple.

the

and standard to some mass of metal. That will slow down the couple and will give greater assurance of having the couple and the standard at the same temperature. For the purpose of standardizing, you are not interested in very great speed and the mass of metal will help to avoid having the couple being checked and the standard at different temperatures.

I think that the thermocouple is capable of giving very satisfactory results when its characteristics are given proper consideration. For survey measurements on cable systems, I think it should be recommended.

E. S. LEE:

There is not much to add to the remarks of Mr. Stein, as he has covered the matter very carefully. We have collected all of the various types of these instruments together and have them in the substation on Grand Avenue, and we would be glad to have you come to see them and see what they look like. Some of the gentlemen who have been there said that previously they had but little idea as to what they looked like or how they operated.

As Mr. Stein has said, for survey work the thermocouple is probably the best form of temperature detector. The manufacturer has some problems in designing the proper kind of thing to put in the duct, and that is really where we would like to have some information from you. In the first place, something about maximum temperatures encountered. Some men think it will be 40 or 50 degrees. Others think it will be 110 degrees, so there is a difference of opinion there. Also the kind of stuff you have in the duct. I find there is water, manure and everything else in the duct, whereas some people think it is clean. Whatever you put into the duct must be such that it will not be attacked by the conditions in which it finds itself. Also the matter of the amount of space available.

One man said, "We have only enough room to put a fish line through." Another man has space enough to put a large element through. If there is not extra space enough in a duct already occupied by a cable then we have to use an empty duct.

In order to bring these matters before you, the various companies have made up forms of thermocouple detectors, some of which may appeal to you. One we made up in the form of a multicouple cable having a steel core for strength, so it could be pulled through a duct, say, 500 feet long, and with the junction of a thermocouple spaced every 50 feet, so (indicating on diagram). With the instrument situated in the manhole you can then measure the temperature at each 50 foot point along that duct. That is one form of survey. Some criticisms have been made and some commendation. Another idea suggested was to have a spool arrangement the diameter of the duct holding a thermocouple connected by long lead to the instrument, so (indicating on diagram). The spool can be pulled through the duct any desired distance. We realize this will always be subjected to very rough usage; consequently the

materials of which these thermo detectors are made will have to stand the rough usage. There may be some comments on your part as to what rough usage they will have to stand.

For permanent installations, that is, if you are interested in knowing the temperature of the lead on the cable at a certain point, maybe where the cables leave a station or a substation, either a thermocouple can be used, or we can use the resistance temperature detector in the form of a copper coil similar to the copper coil placed in electrical generators. The leads can be run to an instrument on the switchboard where periodic readings of the temperature can be made by the switchboard attendant when he reads the other instruments.

We also have a temperature indicator operating from a source of A. C. which has the particular feature that it operates with an insulating transformer. If at any time you want to make tests under operating conditions and place the detector on the bare copper so that it is subject to high voltages, then the transformer may be used and the operator will not be in danger due to the high potential.

So I say there are a considerable number of questions the manufacturers are interested in and the answers can come from you if you will only give the information. As has been said, a manufacturer will put out almost any kind of a thing for your needs if he knows what the particular needs are that he has to meet.

Again I ask you to come to the exhibit for your own good, to find out what these things are. We have the thermocouple, the resistance temperature detector, and the instruments that go with them; also a vapor thermometer, together with the instrument that goes with it, and other instruments on exhibition for your purposes.

MR. ROPER: Professor Scott raised the question of the progress in the art of cable manufacture and so forth, and mentioned the record of burnouts as indicating a lack of progress. It is perfectly good criticism, as far as the records go. Most of the progress in the art of cable manufacture has occurred within the last five years, in which time there has been several times as much progress as there was in the previous 25 years. As the result, the companies that have been buying cable with low dielectric loss have only a small amount of such cables in service, due, in part, to the war, which prevented our getting any cable whatever, and the small amount that we have been able to get since then has been on account of our financial condition. However, that matter has been taken up in the Underground Committee, and it has been arranged so that next year the reports, which are now published, including all kinds of cable, will hereafter separate the sheep from the goats and we will have records separately of the high-grade modern cable and the somewhat lower grade cable of the previous years.

Mr. Shaw raised the question of the rough usage the cable gets during installation. The N.E.L.A.

cable specifications have a bending test which is intended to imitate and be a little more severe than the rough usage the cable gets during installation, and I might add the English specifications have at bending test that is even more severe than the N.E.L.A.

In discussions with the manufacturers of cable, before we placed orders for 33,000 volt cable, one very interesting point was brought out by one manufacturer who stated, in very positive terms, that his experiments, covering a period of years, indicated that if, after our 33,000 volt cable was installed, we would, by means of lower voltage current, say 12,000 volts-heat that cable up to somewhat near its maximum operating temperature and allow the impregnating compound, which might have been disturbed or perhaps cracked if it was installed at low temperature, like paraffin, or some other compounds will do if this cable was heated up to about its maximum temperature so as to liquify the impregnating compounds and allow it to readjust itself so as to fill up all the cracks and voids that might occur, due to bending or rough usage or stretching, then the cable, in that condition, in all probability, would be just as good as the cable was when it was at the factory. In other words, this preheating of the cable before putting on the high voltages, would offset all of the advantages due to rough handling.

G. B. SWARTHOUT: I would like to ask Mr. Roper or any of the other gentlemen who are ordering this cable, if they are considering round cable on the high voltages or high sector cable in order to reduce the diameter.

MR. ROPER: In Chicago installations we are limited to three-inch lead sheathes. That is the largest that we can get into our ducts. If we used a round conductor we would have a comparatively small conductor, but by using sector conductors we are able to get 350,000 C. M.

MR. RICKETTS: What voltage?

MR. ROPER: 33,000. One object is to reduce the price of the cable. That is comparatively small. amounting to three or four per cent, perhaps; the reduction is principally in the amount of lead. although there is some reduction in the paper. The other reason is that it enables you to get a very much larger conductor in the same size lead sheath.

HAROLD K. WELD: Mr. Chairman, I never spoke before in your meetings, but I feel that if a criticism has been made of the work of this committee, 1 rather resent it. However it may or may not be justified, my own feeling is that the Committee deserves a great deal of commendation. I am not an operating man and am not on the Committee, but represent one of the manufacturers of cable and I know that our people have worked with the Committee, and other manufacturers have done the same.

and I know the Committee has done a great deal of original and valuable work as a new Committee. It seems to me that you will agree, and your acceptance of specifications T4-20 as rapidly as they have been adopted, would seem to prove that the Committee has done a great deal of constructive work in the short time it has been in your service. I feel impelled to make these comments in order to get my own conscience clear in the matter.

PROF. SCOTT: Mr. Chairman, I did not have any "conscience." I was not commenting on the work of this Committee, but the whole situation as to what the National Electric Light Association has been doing the last fifteen or twenty years. If this is a new Committee it may be something has not been going quite right.

deserves a great deal more work, a great deal more in quantity and it must be of high quality.

THE CHAIRMAN: As I understand it, the only criticism of the work and the report of the Committee is the criticism just referred to. I have nothing to say in defense, but I omitted the same thing when we opened the meeting this afternoon, and I continue to ackowledge the fact, that we don't know much, and that is my explanation of why the report is not very long. I really think that is the proper policy. If you don't have much to say, don't say much.

MR. ROPER: I move that the meeting stand adjourned.

(Motion seconded and carried.)

(The meeting was thereupon, at 4:30 p. m.,

As amended and adopted at the Forty-fourth Convention, Chicago, Illinois, June 1, 1921

ARTICLE I-NAME

practitioners of engineering and related sciences or of other professions who are interested in the art of applied electricity. They may become or remain members only upon the invitation and approval of the National Executive Committee. They shall have

SECTION 2. Class A members shall be regularly incorporated public service companies or individuals engaged in producing and supplying electrical energy for light, heat or power for public use. They shall be entitled, through their regularly accredited delegates, to attend all meetings of the Association,

to vote and to hold office.

SECTION 3. Class B members shall be officers or employees of Class A members, elected or continued from year to year with the written approval of the Class A member with which they are connected. They shall have all the privileges of Class A members, except the right to attend and to vote at the executive sessions of the Association, but they shall be allowed to attend such executive sessions upon the written request of the Class A member vouching for their membership.

SECTION 4. Class C members shall be officials of Public Service Commissions, instructors, teachers or

right to hold elective office and to attend or to vote at executive sessions.

SECTION 5. Class D members shall be companies or firms engaged in the manufacture of electrical apparatus or equipment for the production or use of electrical energy. They shall be entitled, through their regularly accredited delegates, to attend all meetings of the Association, to vote and to hold office.

SECTION 6. Class E members shall be officers or employees of Class D members, elected or tinued from year to year with the written approva! of the Class D members with which they are connected. They shall have all the privileges of Class D members, except the right to attend and to vote at the executive sessions of the Association, but they shall be allowed to attend such executive sessions upon the written request of the Class D members vouching for their membership.

SECTION 7. Class F members shall be companies electrical or mechanical engineers, publishers, assoor firms of electrical jobbers, contractors, dealers, ciations or others corporations or individuals—who are interested in advancing the use of electrical energy. They shall have all the privileges of Class A and D members, excepting the right to hold elective office, and to attend or vote at executive sessions

SECTION 8. Class G members shall be officers or

employees of Class F members, elected or continued from year to year with the written request of the Class F member with which they are connected and proposed and recommended by the Class A member in the territory where the applicant resides. Where no Class A member's recommendation or disapproval can be obtained, application for membership may be recommended by a Class D member, the Presiding Officer of the Geographic Division, the State Association, or a National Section. They shall have the same privileges as Class F members.

SECTION 9. Foreign members shall be individuals or corporations not residents of North America. engaged in the central station industry, or interested