Document YGjz0oqnjdnn5E2NGwnM9x0by

194 CHAPTER 11 \ IOASt J l *4 W - ` Number of Caro Table 1. Ringelmann Smoke Chart Spa'Cings Thickness of Lines, mm Distance in Clear Between Lines, mm 1 1.0 2 3 4 2.3 3.7 5.5 .9.0 7.7 6.3 4.5 ' Photo-electric Cell The photo-electric cell is used in some apparatus developed for smoke density recording in large plants. The same device is included in the testing equipment for domestic oil burners described in National Bureau ovf Standards, Cvuoimuumiecricciiaiiil oSttEannQda^rrdd LCiS^/755*4-42266. Under Laborator^y _Te__s_ts this npnuhblliirc-aattiiromn contains t<ah-e- *fo-llo- wing sect'ion: "Smoke Determinnaattiioonn:'. --After combustion has reached equilibrium, the amounti--------------- --------------- of snioke in the flue gases, when viewed' lengthwise through 4 feet of the smoke pipe in accordance with the Underwriters' Laboratories, Inc., Standard for Domestic Oil Burners (Subject 296), March 1934 and subsequent re visions, shall not reduce the output of a standard photoelectric cell from 9 microamperes, with a clear smoke pipe, to less than 8 microamperes." The commercial standard also requires that during a test after installation, the burner shall operate without visible smoke at the chimney top. A method of evaluating smoke produced by pot type oil burners was developed for the Institute of Cooking and Heating Appliance Manu facturers by R. N. St. John. A glass rod is interposed between a light source and a photo-sensitive cell both before and after being exposed to the flue gases from a heating device. The diminution of the light trans mitted by the rod due to the deposit of soot on its surface causes a reduc tion in the cell emf which is taken as an index of the concentration of smoke in the flue gases. A description of the method is contained in National Bureau of Standards Commercial Standard CS104-46 67. Sound and Vibration Measurements Approximate measurements of sound intensity can be made by aural methods. The ear is used to compare the measured noise with sounds of known strength. Electrical devices in which the ear plays no part furnish the most satisfactory means of measuring noise intensities. The sound meter consists essentially of a microphone coupled to an amplifier designed with an ear-like response. The output of the microphone is read on a sensitive direct current milliammeter graduated to read directly in decibels. In struments of this type if connected with suitable band pass filters can be used to study the intensity of the sound over its entire range of frequencies. Electrical instruments are available for measuring the frequency, amplitude and acceleration of a vibrating mass. They are usually more convenient and accurate than the vibrating reed tachometer and the seismic type displacement meters and accelerometers which can also be used for this purpose. Sound level meters are discussed, in several text books 5S- 69 and standards M. - instruments and Measurements 195 REFERENCES i--For a comprehensive treatment of temperature measurement the reader is referred to Temperature, Its Measurement and Control in Science and Industry, a symposium sponsored by the American Institute of Physics and published by Reinhold Publishing Corp. *--Errors in the Measurement of the Temperature of Flue Gases, by P. Nicholls and W. E. Rice (A.S.H.V.E. Transactions. Vol. 35, 1929, p. 473).- *--Temperature Measurement (A.S.M.E. Power Test Code, Part 3). 4--Investigation of Warm Air Furnaces and Heating Systems, by A. C. Willard, A. P. Kratz arid V. S. -Day (Illinois Engineering Experiment Station, Bulletin No. 120). 5-- Measuring Heat Transmission in Building Structures and a Heat Transmission Meter, by P. Nicholls <A.S.H.V.E. Transactions, Vol. 30, 1924, p. 94). 6-- Parallel-Connected Thermocouples for the Testing of Gas Appliances, by Walter B. Kerk and George J. Pacanovsky (Gif, September, 1939, p. 51). 7-- For a comprehensive treatment of pressure measurement see Experimental Mechanical Engineering, Vol. 1, Chapter IV, by Diederichs and Andrea. --Standard Test Code for Centrifugal and Axial Fans, Edition of 1938. See also Standard Code for the Testing p. 363). of VCentrifugal and Disc Fans (A.S.H.V.E. Transactions, Vol. 29, 19.23, p, 407; Vol. 37, 1931. 9--Fan Engineering, Buffalo Forge Company, 4th Edition, Chapter 2, p. 104. 10-- Illinois Micromanometer (University of Illinois-, Engineering Experiment Station Bulletin No. 120, P. 91). ' * *--The Weathertightness of Rolled Steel Windows, by J. E. Emswiler and W. C. Randall (A.S.H.V.E. Transactions, Vol. 34, 1928,' p. 527). * Pressure Measurement (A.S.M.E. Power Test Code 1936. Part 2, Chapter 2). 13--The Measurement of Static Pressure, by C. J. Fechheimer, Mechanical Engineering, August, 1927. ,4--For technical data refer-to Fluid Meter Reports, Parts 1--1937, 2--1931, and 3--1933 (American Society of Mechanical Engineers). 1 s--Technical Notes No. 546 (National Advisory Committee for Aeronautics, November, 1935). 16-- The Characteristics of Double Pitot Tubes, by F. R. Ingram, E. Diez-Canseco and L. Silverman (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, November, 1942, p. 708). 17-- Standard Code for-Testing and Rating Steam Unit Heaters (A.S.H.V.E. Transactions, Vol. 36, 1930, p. 165), adapted-Jahuary, 1930, by A.S.H.V.E. --A.S.H.V.E. Standard Code for Testing and Rating Steam Unit Ventilators (A.S.H.V.E. Transac tions, Vol. 38, 1932. p. 25), adopted June, 1932. is--a.S.R.E. Standard Methods of Rating and Testing Air Conditioning Equipment, A.S.R.E. Circular No. 13. 20_Air Flow Measurement in the Laboratory, by D. D. Wile. Refrigerating Engineering, June, 1947, p. 515. *1--Discharge Coefficients of Square Edged Orifices for Measuring the Flow of-Air, by H. S. Bean, E. Buckingham and P. S. Murphy (Bureau of Standards Journal of Research, Vol. 2, 1929, p. 561). ` **--Flow Measurement by Nozzles and Orifice Plates (A .S.M.E. Power Test Codes, Chapter 4 of Part 5, 1940). *3--A.S.H.V.E. Research Report No. 1140--The Use of Air Velocity Meters, by G. L. Tuve, D. K. Wright, Jr. and L. J. Seigel (A.S.H.V.E. Transactions. Vol. 45. 1939, p. 645). *4--Temperature, Humidity and Air Motion Effects in Ventilation, by O. W. Armspach and Margaret Ingels (A.S.H.V.E. Transactions. Vol. 28, 1922, p. 103). The Heated Thermometer Anemometer, by C. P. Yaglou (Journal Industrial Hygiene and Toxi cology, Vol. 20, October, 1938, No. 8). A.S.H.V.E. Research Report No. 1165--Development of Instruments for the Study of Air Dis tribution in Rooms, by A. P. Kratz, A. E. Hershey and R. B. Engdahl (A.S.H.V.E. Transactions, Vol. 46, 1940, p. 351). 87--Development of Testing Apparatus for Thermostats, by D. D. Wile (A.S.H.V.E. Transactions, Vol. 42, 1936, p. 349).. 28--The Measurement of Air Flow, by R. O. King. Engineering. London, February 1 and 24, 1924. *9--A.S.H.V.E. Research Report No. 1204--Entrainment and Jet-Pump Action of Air Streams, by G. L. Tuve. G. B. Priesterand D. K. Wright. Jr. (A.S.H.V.E. Transactions. Vol. 48, 1942, p. 241). 30-- A.S.H.V.E. Research Reports Nos. 857. 911 and 966--Measurement of the Flow of Air Through Registers and Grilles, by L. E. Davies (A.S.H.V.E. Transactions, Vol. 36, 1930, p. 201, Vol. 37, 1931, p. 619, and Vol. 39. 1933, p. 373). 31-- A.S.H.V.E. Research Report No. 1162--Air Flow Measurements at Intake and Discharge Open ings and Grilles, by G. L. Tuve and D. K. Wright, Jr. (A.S.H.V.E. Transactions. Vol. 46, 1940, p. 313).