I. Integrated Intensity Measurements for Vibration-Rotation Bands of Carbon Dioxide. II. Total Absorptivity Measurements on Carbon Dioxide at Room Temperature Citation Holm, Robert Joseph (1952) I. Integrated Intensity Measurements for Vibration-Rotation Bands of Carbon Dioxide. II. Total Absorptivity Measurements on Carbon Dioxide at Room Temperature. Engineer's thesis, California Institute of Technology. doi:10.7907/RN61-AX46. https://resolver.caltech.edu/CaltechETD:etd-03232009-081744 Abstract I. This study contains an outline of the experimental measurements performed in order to determine integrated intensities of various vibration-rotation bands of carbon dioxide by use of standard techniques with a Perkin-Elmer spectrometer. II. Total absorptivity measurements on carbon dioxide at room temperatures were made in a pressurized gas cell provided with transparent windows. Item Type: Thesis (Engineer's thesis) Subject Keywords: Aeronautical Engineering Degree Grantor: California Institute of Technology Division: Engineering and Applied Science Major Option: Aeronautics Thesis Availability: Public (worldwide access) Research Advisor(s): Penner, Stanford S. Group: GALCIT Thesis Committee: Unknown, Unknown Defense Date: 1 January 1952 Record Number: CaltechETD:etd-03232009-081744 Persistent URL: https://resolver.caltech.edu/CaltechETD:etd-03232009-081744 DOI: 10.7907/RN61-AX46 Default Usage Policy: No commercial reproduction, distribution, display or performance rights in this work are provided. ID Code: 1075 Collection: CaltechTHESIS Deposited By: Imported from ETD-db Deposited On: 23 Mar 2009 Last Modified: 11 May 2023 20:38 Thesis Files Preview PDF (Holm_rj_1952.pdf) - Final Version See Usage Policy. 40MB Repository Staff Only: item control page

I. INTEGRATED INTENSITY MEASUREMENTS FOR VIBRATION= ROTATION BANDS OF CARBON DIOXIDE II. TOTAL ABSORPTIVITY MEASUREMENTS ON CARBON DIOXIDE AT ROOM TEMPERATURE Thesis by Robert J. Holm Lieutenant Colonel, United States Marine Corps In Partial Fulfillment of the Requirements For the Degree of Aeronautical Engineer California Institute of Technology Pasadena, California 1952 ACKNOWLEDGEMENTS The author wishes to extend his appreciation to Dr. & S. Penner, under whose direction this work was conducted, and to Mr. D. Weber for help with the experimental work, ii ABSTRACT I. ‘This study contains an outline of the experimental measurements performed in order to determine integrated intensities of various vibration-rotation bands of carbon dioxide by use of standard techniques with a Perkin~Elmer spectrometer. II. Total absorptivity measurements on carbon dioxide at room temperatures were made in a pressurized gas cell provided with trensparent windows. Lit TABLE OF CONTENTS Acknowledgements i Abstract ii Table of Contents ili fable of Figures iv Symbols vi I. Integrated Intensity Measurements on Carbon Dioxide 1 A. Introduction and Summary 1 B. Methods For the Experimental Determination of Integrated Intensities 2 C. Experimental Studies 6 D. Comparison With The Results of Other Investigators 7 BE. Calibration of Perkin-Elmer Spectrometer with Sodium Chloride Prism 9 II. Total Absorptivity Measurements on Carbon Dioxide At Boom Temperature 10 A. Introduction and Summary 10 B. Basic Radiation Laws | 13 CG. Total Absorptivity Determinations On Carbon ‘Dioxide at Room Temperature 15 D.. Comparison with the Results of Other Investigators 19 Figure l. 26 3. 4. 5e 6. 76 8. 9. iv TABLE OF FIGURES Title Schematic Representation of Infrared Absorption Gell Used to Measure Intensities of Gas Mixtures @/2.303 as a function gf pf for the CO, band with center at 5109, cm” Zl ° XK = .426 + .043 om” - atm at 298 K. (3.57 om cell length, Pa = 90 psia) @/2.303 as a function of pf for the C0, band with center at 4983 cm!. X= 1.01 + .10 em? - atm at 298°K, (3.57 om cell length, p, = 500 psia) @ /2.303 as a function of pf for the 60g band with center at 4860 cm). A= .272 + 027 om? ~ atm at 298°K. (3.57 om cell length, Py = 500 psia) @/2.303 as a function of pf for the CO. band with center at 3716 om. 1 X= 42.3 + 4.23 em? - ata” cell length, pm = 500 psia) at 298°K. (.5 om @ /2.303 as a function of pf for the 00g band with center at 3609 om@. ° X= 28.50 + 2.85 cm ~ atm at 298°K. (.5 om cell length, P_ = 500 psia) @ /2.303 as a function of pf for the O00. band with center at 2349 em™*, A= 2706 + 270 om” — atm@) at 298°K. (5.15 cm cell length, p_ = 700 psia) 8/2.303 as a function of p/ for COg in the region between 2000 _gnd 2160 cm~i, ° x = 0147+ .047 om” - atm! at 298K. (3.57 and 6.72 em cell length, Py = 500 psia) 6 /2.303 as a function of p? for COg in the region between 1800 and 2000 em7l, X= .083 + .008 cum? = atm! at 298°K. (6.72 ca cell length, p, = 400 psia) Page 26 a7 30 Figures 10. ll. 12. 13. 14. 15. 16. 17. 18. 19. TABLE OF FIGURES (Cont'd) Title @ /2.303 as a function of pf for CO, band with center at 668 cm7) including week neighbor- ing bands with centerg at 720, 667 and 618 cm. & = 171.5 417.1 cm” = atm™ at 298°K. (1.985 cm cell length, p, = 500 psia) Calibration curve for infrared spectrometer with Nec? prism Calibration curve for infrared spectrometer with NaC prisn Block diagram of apparatus for measurement of total absorption of infrared radiation Absorptivity x as a function of for various fractional pressures of CO>o at room temperature. (The COp was pressurized with nitrogen) Absorptivity & as a function of pf for CO. at room temperature and a total pressure of one atmosphere Absorptivity OC as a function of pf for Cp at room temperature and a total pressure of one atmosphere Absorptivity &K ef 602 at room temperature as a function of pf at various total pressures Comparison of experimentally determined absorptivities as a function of optical density for C05 at atmospheric pressure and room temperature with the results of studies carried out by Hottel and Mangelsdorf Comparieon of experimentally determined absorptivities as a function of optical density for C0. at atmospheric pressure and room temperature with the results of studies carried out by Hottel and Mangelsdorf Page 32 36 37 38 39 It u Wi i] tt vi SYMBOLS integrated intensity spectral absorption coefficient wave number quantum number transmitted intensity incident intensity partial pressure optical path length apparent intensity without absorber apparent intensity with absorber apparent integrated intensity ph fa’ total pressure micrometer screw turns defined spectrometer constant Restrahien wave number optical density energy emitted by a blackbody at temperature T at wave length A energy emitted by a blackbody at temperature T at wave number WwW ° oe Qa eo re) m Qa F €- BR wow A Wt ul il vii SYMBOLS (Cont'd) wave length wave number physical constants velocity of light Planck's constant Boltzmann's constant absolute temperature Stephan Boltzmann constant enissivity spectral intensity of emission from greybody engineering emissivity recorder constant defined recorder constant recorder deflection absorptivity globar temperature I. INTEGRATED INTENSITY MEASUREMENTS ON CARBON DIOXIDE A. Introduction and Summary The importance of gas radiation in effecting heat transfer be~ tween a gas and its surroundings, particularly when the gas temperature is high, has been recognized for some time. However, accurate emissivity data are generally not available for use in engineering calculations of heat transfer. Recently attempts have been made to calculate gas emissivities theoretically from spectroscopic data. It is the purpose of the present study to provide some of the basic data which are needed for the theoretical calculation of emissivities of carbon dioxide. Quantitative infrared intensity measurements have been carried out for the more intense vibration-rotation bands of carbon dioxide using helium as a pressurizing agent, use of standaré techniques. Measurements were made by The results are summarized in Table I. Table I, Observed Integrated Intensities* of Carbon Dioxide Band Center Integrated Bend Center Integrated (em™=) Intensity (em~+) Intensity (on? atm at 298°K) (cn? atm~lat 298°K) 5109 043 1252) combined 83 4983 1.01 1886 4860 027 720 3716 42.30 668 )combined 171.50 3609 28 .50 647 2349 — 2706.00 618 2137 2094)combined 147 2074 | * Observed intensities are accurate within + 20%, -2= Be Methods For the Experimental Determination of Integrated Intensities Integrated intensities of the infrared vibration-rotation bands are required for the theoretical calculation of gas emissivities and radiant heat transfer. The integrated intensity c{( for a given vibration-rotation band ie defined by the relation XK = Je aw (1) where P w represents the spectral absorption coefficient at the wave number (vu. Although the limits of integration should extend from = © to+ © it is sufficient to restrict integration to a narrow wave number interval bracketing the band center because Puy decreases very rapidly with Ww in the wings of the vibration-rota- tion bands. ‘The integrated intensities for various vibration=-rota= tion bands will be identified by appropriate changes in vibrational quantum number. ‘or example, the intense v3 ~- fundamental of carbon dioxide arises as a result of the transi tion* (2) vy, = OFV, = 0, Vo = OP Vy = 0, Az o-~f= ©, Ve = 0 -7Vg = 1 and has a band center at 2349.3 on™, The corresponding velue of the integrated intensity is then identified by the symbol 2 0 a aw on men en Sewe * For details concerning spectroscopic notation of polyatomic molecules see, for example, G. Herzberg, rared and Spectra, D. Van Nostrand Co., New York (1945). ~s= ° ° X (0,0,0 —? 0,0,1) The integrated intensities of other vibration-rotation bands may be identified similarly. a) ‘The Method of Wilson and wes? For monochromatic radiation it is well known that ly = Igy exp (-P,, pl) (2) where Iw is the transmitted intensity at the wave number wi when the incident intensity is I,,, , p is the partial pressure of the absorbing gas and 54 represents the optical path length. Hence the integrated intensity becomes A = (ph) IE (Iow/ I) aw (3) AW where the integration in Bq. (3) is to be performed over the entire effective width gw of the vibration-rotation band under study. The apparent intensities observed without absorber and with absorber, when the instrument is set at W , are not Tow and I w respectively, but rather fow = J rw" ge(w, wi)aw! (4) ty = pw e(w,w') dw! (5) and ~40 where g(W, W!') represents the fraction of light of actual wave number ww! to which the instrument responds when it 1s set at Ww. Some of the difficulties inherent in the calculation of P,,, do not arise in the determination of the integrated intensity. Fron experimentally determined values of Tw and t w it is possible to determine an apparent integrated intensity od ' which is defined by the relation a = (ph) /ts (mw/ ty) dw= B/pf (6) Wilson and Weis” have shown that Len a = ro ph 0 when a number of specified conditions are met, These conditions include the requirement that Toy be independent of wW in the resolved spectral range, a condition which can be approached closely by eliminating atmospheric absorption and using sufficiently narrow spectrometer slits to give high spectral resolution. In addition to requiring constent Ty. , Eq. (6) will hold only if either the variation of P,, with (uv can be neglected in the spectral range or the resolution of the instrument does not vary appreciably over the vibration~rotation band under study, Of these two requirements the latter constitutes an intrinsic property of the instrument. The variation of Py in the resolved spectral interval can be minimized a by pressure broadening, i.€., a3 pf is decreased, of ' will approach ef more rapidly, the higher the constant total pressure at which the observations are made. | As the optical density is decreased, the plot of =] vs pd may show considerable curvature. This fact introduces an appreciable error into the extrapolation required to determine & . At sufficiently high total pressure p,, the variation of 6 with pf should follow a linear relation in accord with the fact that the true integrated intensity is measured at every value of the optical density and Eq. (6) should apply directly. By proceeding according to Wilson and Wels 2) the result of '-» cK as Pp is increased can be demonstrated, (3) The true value of the integrated intensity eC can be obtained either by extrapolating oc! to zero values of pf at constant Pp oF by finding the limiting value of g¢!' at constant optical density as the total pressure is increased. b) The Self-Broadening Technique of Penner and weber *? Infrared transmission studies on pure gases have the obvious advantage of eliminating the possibility of experimental error resulting from imperfect mixing or from the occurrence of adsorption= desorption phenomena, On the other hand, they possess the severe disadvantage of always involving the effect of significant self= broadening associated with increased pressure of the absorber. Howe ~6= ever, by suitable choice of test cell length it is possible to utilize self-broadening to obtain quantitative infrared intensity data. In general, the required cell length is shorter when the vibration-rotation band is more intense. C. Experimental Studies a) Apparatus A Perkin-Elmer Model 12C single beam infrared spectrometer with lithium fluoride, sodium chloride, and potassium bromide prisms was used for transmission measurements. Incorporation of automatic slit drive over the wavelength interval used for study was found to save considerable time in experimental work. Pressure readings were performed by use of a Wallace and Tiernan precision manometer for the pressure range 0-800 mm of mercury (+ .2 mm) and 0-1000 psig by use of a Marsh gage (+ 2 psig). The cell and window assemblies were machined from 1888 stain= less steel stock. Neoprene O-rings and neoprene or teflon gaskets were used to support the cell windows. ‘The principal features of the cell are shown in Fig. 1. ‘The right end plate is provided with a special tap to permit flushing with nitrogen of the outside of the cell in the light path. This same end plate is fitted with a flange to slide into the absorption cell slot provided on the spectro- meter, A flexible collar is inserted between the other end plate and the globar source. ‘The collar also has a fitting for nitrogen -_ um The cell is provided with a window assembly as shown and is large enough to permit incorporation of stirring rod with perforated end plate. In each experiment care was taken to assure uniform mixing of gases in the cell by adequate use of the stirrer. It was assumed that a uniform gas mixture had been obtained when additional stirring produced no measurable change in transmission, Details of wavelength calibration of the priam spectrometer using a sodium chloride prism are given in Section 3. bd) Summary of Experimental Data For the vibration-rotation bands of carbon dioxide on which experimental measurements were performed the quantity @ [2.303 has been plotted as a function of p g in Mgs. 2 to 10. Correspond= ing integrated intensities have been given previously in Table I. ier son With The Results of Other Investigator The observed intensities of vibration-rotation bands of carbon dioxide are compared with the results of other investigators in fable II. Reference to Table II shows that the data are in excellent agreement with the results cf other investigators. -8~ Table II. Observed Intensities of Carbon Dioxide ———- ane —— ed Integrated Intensity of (om@ atm} at 298K) (em™4) set al 2996 Grewfora (”) Study (1941) + 10% + 20% (1951) (1952) 5109 .426 4983 1.01 4860 272 3716 39.0 42,3 3614 27.0 28.5 2349 2867.0 2693.0 2706.0 2137 2094 }emmsoe 614? 2074 0.14 (P and Q) 2074 -05 (Q only) ogg aoe +005 poonbined ° 720 . . 171.5 668 187.0 161.0 combine’ 647 618 a. E, Calibration of Perkin-Elmer Spectrometer with Sodium Chloride Prism In the wave number calibration of an infrared spectrometer it may become necessary to make use of the relation between micrometer 6crew turns and wave number in wave number regions where no calibration points (absorption bands or lines) exist or are available. In the present calibration it was necessary to extrapolate the micrometer screw tums vs. wave number curve from the carbon dioxide band at 667 on to regions near the absorption limit of the sodium chloride prism. This was done using the method of McKinney and Frieder (®) whose empirical equation is T= 1, -B w° ~w2)t (7) where T is micrometer screw turns and T, is the ordinate intercept at Ble” - wy = 0. Here Ww, is the Restrehlen wave number depending on the prism material and w is a known or measured wave number. Seven absorption maxima of ammonia and carbon dioxide were used for calibration and (w,” ~ wy was calculated and plotted against micrometer screw turns. For sodium chloride the value of Ww, 18 125 on The constants q and B are determined from the known absorption maxima, Equation (7) is used to extend the calibration curve of T vs w . The correction term for short wave length absorption was neglected for the present purpose. Figures 11 and 12 are reproductions -10— of original calibration graphs in which the abscissae are, 2.~-1 respectively, Ww and (we" - w) , whereas each ordinate rep- resents micrometer screw turns. ~ll~ II. TOTAL ABSORPTIVITY MEASUREMENTS ON CARBON DIOXIDE AT ROOM TEMPERATURE A. Introduction and Summary The calculation of radiant heat transfer from heated carbon dioxide requires the use of experimentally determined absorptivity data. The total absorption of radiation by carbon dioxide has been reinvestigated at various optical densities at different total pressures and at room temperature. <A complete investigation could not be carried out at other temperatures because of experimental difficulties with the gas cell and amplifying system. The measured values of the total absorptivities are given in Table III. -12- Gee* S7°OT o7°SS 7Te* LT°6 c9°87 OgT° 09°9 TO°SE S7T° 70°7 ett® 60°% 20T® €60°T 060° Te9° 040° Tve° g70* Sg70° T7*t?e €eT° 9L°% YOT° €v°T 760° S7L° 980° Oc7* 290° 79T° €70° STEO* 09°7T TIT° L7°T cOT* T9L° Ogo* oge* 9L0° Oce* eS0° LL80° S€o° 94TO° 03° €OT° 696° 980° 967° 640° 652° 990° S6YT° - TLS0° 00° STIO* | g0°S S60° coL* 640° €9¢° 040° O6T® €90° S60T° 6£0° 8T70° Le0° T7800° CLE 780° S77° 490° oEe° 950° SO2T° €S0° 690° gzo° 9920° €20* 7€S500° 9E°S% T90° 68T° 0S0° 9L60° T70° OTSO° 8E0° 7620° 7Z0° Auton STO* 9%Z00° T (mye 4Z) (m9 43) ("72 42) (42 45) (ui4-8 92) (w38 45) (we) AF » yal » ri} ya ir ya 7 ya » ya d 7, © z @ c (4 t= as a} peter = W/ Ma soz? = "4/Pa ogst? = "ay a gesoe = Tay a | zetor = Tay a *(@PFXOTp uoqavo go AqFsuep [uoTydo 03 Suezjer Y d) seinssedy [BIO], JUSJeZTTq pue samyesedmey wooy ye SPTXOTq UcgTeg Jo yo AqTATYdacsqy “III e1qsL ~13~ Be Basic Radiation Laws The spectral distribution of radiation from a blackbody is given by Planck's radiation tew'?) -5 -1 R, dA =o) A [exe (ep/A T) - yf aa (7) where R A aA is the energy emitted from a blackbody at temperature T per unit time per unit area in the wave length interval from A to A plus dA throughout a solid angle 277 steradians. c, and Cy are physical constants whose values are given below: (10) 8 2 c= 21 ch” = (3.732 + .006) x10 erg cm sec; ey = ch/k = (1.436 + .001) om °K; ~10 ~l c = velocity of light = (2.99776 + .00020) x 10 cm sec ; h = Planck's constant = 6.62 x 10727 erg sec; ~1L6 o ~1 k = Boltzmann's constant = 1.381 x 10 ergs per molecule K . -1 Equation (7) may be expressed in terms of wave number W(-) ), w=] Ry dw = ow” [exp (c,w/T) - J aw (8) where R,, dW is the energy emitted from a blackbody at tempera~ ture 7 per unit time per unit area in the wave number interval from W to W plus dW throughout a solid angle 2 71T steradians. ~1l4— The total intensity of radiation emitted by a blackbody over all wave lengths is given by Stephan's law co J aw = oa (9) fe) where @ represents the Stephan~Boltzmann constant and has the numerical value 1) (5.67283 + .0037) x 1075 erg em™2 4 -1 oF sec 27 x*/1507h"), For a greybody the emissivity £& is independent of wave number, 1.0., R { x= id R (10) w W where Rw 1 is the spectral intensity of radiation emitted from a greybody. The engineering emissivity or absorptivity for diatomic and polyatomic gases is defined by a relation similar to Eq. (9). ‘Thus, if I w is the spectrally emitted intensity from a non-black and a non-grey source, then the engineering emissivity E is given by 69) B= J(u [/o- )aw (12) r) where I is By 1 - exp (=P iv pf )] ’ Py is the spectral absorption coefficient and pf is the optical path density. Equation (11) can be written more explicitly as a sum over the contributions to the total emissivity from separate vibration= rotation bands. Ts, let , I ‘ f ’ AW = AW (vw, Vor Ve —> Ve Yop Vg) represent the effective ~15= width of the vibration-rotation band arising from the transition ) » fy Vy» Vox Vg —> Vy» Vos Vae0 Then 1 OM, Ju [a= ep oe, Dy, aw (13) Su’ where the quantum numbers must conform to the selection rules for all allowed vibrational transitions. Quantitative calculations of E are exceedingly difficult to carry out. Ce Total Absorptivity Determinations on Carbon Dioxide at Room Temperature An apparatus has been built for the measurement of absorptivity and emissivity of carbon dioxide. ‘The system consists of a source of infrared radiation, a gas cell in which temperature and pressure may be controlled and a non-selective receiver. ‘The signal from the receiver or detector is amplified using chopped radiation for stabilization. ‘The percentage of transmission is found by comparing voltage output from the detector for an empty cell with voltage output from the detector for the same cell under test conditions. A recording potentiometer (Speedomax) is used to indicate voltage. A block diagram of the apparatus used for study of absorption and emission is shown in Fig. 13. The source of radiation used is a globar unit which has a continuous emission spectrum in the infrared region. ~16= The globar temperature must be held within close limits to reduce fluctuations in radiation. Power supply to the globar is regulated by a Sola constant voltage transformer. The globar, gas cell, and detecting thermocouple are placed in a wooden chamber which is flushed with nitrogen to prevent light absorption by atmospheric water and carbon dioxide. The cell is fitted with potassium chloride windows which allow transmission at wave lengths longer than 20 microns, The detector is a thermocouple which develops a signal of 100 microvolts with full globar input. Sensitivity of the thermocouple is specified as six microvolts per microwatt of incident radiation, This thermocouple is of the same type as that used in the Perkine Elmer Model 12C Spectrometer and is reported to be linear in output over wide variations in light intensity at all wavelengths in the near infrared region. The thermocouple is sensitive to ambient temperature changes. Drift end instability produced by such changes are avoided by chopping incoming radiation at 13 cycles per second, Thus a low frequency A.C. amplifier may be used to amplify the very low level signal from the thermocouple. The A.C. signal is later rectified and filtered to recover information regarding signal amplitude. Contacts for the synchronous rectifier are operated by means of cams on the shaft of the synchronous motor used for the rotating shatter, Emissivity as well as absorptivity may be measured with this system. For emissivity measurements it is only necessary to place the light chopper disk between the sample and the thermocouple rather than between the globar and the gas sample. Since percentage of transmission is measured by noting the difference in radiation intensity received when the cell is evacuated and the radiation received when the cell contains gas at known temperature and pressure, it is important that measurements be made within the limits of linearity of the detecting and amplifying system. There is no easy means available for the measurement of absolute radiation intensity received at the thermocouple. The amplifier and Speedomax were found to be linear with respect to input signals from the detector. Percentage of absorption by carbon dioxide at the temperature and pressure used was found to be of the order of 25% or less. In order to get reliable data it is necessary that noise and drift be low in comparison with variations in signal strength arising from changes in absorption of radiation. Noise and drift in the instrument were reduced to below the 1% level. 10) Previous investigations’ were carried out at a total pressure of one atmosphere while varying the partial pressure of the absorb- ing or radiating gas. We have investigated absorption of radiation at room temperature at total pressures up to 55 atmospheres. ~18= Let D= recorder deflection for the filled gas cell and,D, = the deflection for the empty cell, KE= recorder constant, tT = globar temperature, E g = emissivity of source, 7~= Stephan-Boltzmann constant, of = absorptivity and K' = K/o-. Then ED = OE, oat (14) and, if €,=1, = ¥,/2, (15) When the gas cell contains absorbing gas and g 37 1, then K'D = (eat (16) ao = Cae - K'D)/a0 (17) da =le D/D, (18) It follows from Kirchoff'ts law that the total absorptivity and emissivity of the carbon dioxide are equal to each other at equilibrium. At room temperature it has been assumed that the emission of radiation from carbon dioxide is negligibly small compared with the intensity of the transmitted incident radiation. The results of total absorption measurements are presented in fablesIIt end IV and are plotted in Figs. 14 to 17. Table III and Fig. 14 contain a summary of the experimental data which were actually obtained. Table IV and Megs. 15 and 16 contain results applicable to a total pressure of 1 atmosphere. In Fig. 17 the absorptivity << is plotted as a function of optical density with the total pressure Pm treated as a variable parameter. Reference to Mg. 17 shows that o( is not a sensitive function of the total pressure at pressures in excees of about 3.73 atm. fable IV. Absorptivity of Carbon Dioxide at a Pressure of 1 atm end at Room Temperature pf pf (ft~atm) Absorptivity < (ft-atm) Absorptivity of 10 2221 4 2081 8 197 2 2064 6 0172 ol 2054 4 2148 08 2050 2 0122 06 2045 1.5 0113 204 2039 1.0 2103 02 030 8 -098 01 022 6 092 D. Comparison with the Results of Other Investicators The experimentally determined values of co at a total preseure of 1 atm are compared with the results of studies carried (11) out by Hottel and Mangelsdorf in Table V and in Mgs. 18 and 19, -20- Since the limit of our probable error is + 10% and those of Hottel and Mengelsdorf + 20%, the agreement between the independently determined experimental data may be considered to be satisfactory. Table V. Absorptivity of Carbon Dioxide at Room Temperature at a Total Pressure of 1 Atmosphere. ease Absorptivity << pl Hottel and (ft atm) Mangelsdorf Present (1935) Study 10 ooel 8 2197 6 0172 4 01? 2148 2 ol5 L122 1.5 014 0113 1.0 «128 0103 8 0120 .098 26 e111 092 24 2100 081 02 083 067 ol 2068 2054 «08 0064 2050 ~06 -057 2045 204 -050 2039 02 038 ~030 OL .0285 022 2008 0252 2006 0219 0004 «O17 l. 3. 4. 5. 6. 7. 8. 10. ll. oa es REFERENCES G. Herzberg, “Infrared and Raman Spectra, D. Van Nostrand Coe, New York (1945). B. Be. Wilson, Jr. and A. J. Wells, J. Chem. Phys., 14, 578 (1946). 8. S. Penner and D. Weber, J. Chem. Phys., 19, 807-816 (1951). A. M. Thorndike, A. J. Wells, and EZ. B. Wilson, Jr., J. Chem. Phys. 15, 157 (1947). A. M. Thorndike, J. Chem. Phys. 15, 868 (1947). D. F. Eggers Jr. and B. L. Crawford, J. Chem. Phys., 19, 1556 (1951). D. S. McKinney and R. A. Friedel, J. Opt. Soc. Am. 38, 222=225 (1948). L. Page, Introduction to Theoretical Physics., D. Van Nostrand Co., New York (1935). A. N. Lowan et al, “Miscellaneous Physical Tables", WPA Project No. 65~2-97=33. (1941). B. Schmidt, Forsch. Geb, Ingen. 3, 57 (1932). H. C. Hottel and H. G. Mangelsdorf, Trans. A.I.Chem. Engineering, 31, 517 (1935). H. C. Hottel and V. C. Smith, Trans. A.S.M.E., 57, 4 (1935). H. C. Hottel and R. B. Egbert, Trans. A.S.M.E., 63, 297 (1941). G B. yneherts Sc. D., Thesis in Chemical Engineering, M.I.T. 1941), ZI Lo LON Tal (Fagen EEDA Spates N : bs) ANN SSE meg mN M MN x ~ by x N ' H| inj N KY KY hd q \ N Ni N ty N N N ‘ N N N N IN U 4 y | 7 D cman sun SSE YS Fie. 1. Schematic representation of infrared absorption cell used to measure intensities of gas mixtures. iti { } ' ; i t | | ' ' ; | i { CRATES Urabe Ditiss | -ccth Hah Sones dalacehs cieeietareamanion ia Wiad Yo 2 a DB uy AST eer SS San fisted | elt Sat Sree Sete Rar See ate a OG BG An eas ae ee eames goa Peg an eie MOL 2 Mag Se ere gece Ph woop ; : se i. ana aa ot EHR SREL 2S Be i : i t 4 ; i ; i i i i u paris i 7 23 st rece G5 io. 8 Buna E Bettas too Ree Seas Hees abuses Suse ates MES; oe : { RADIATION ROLAPING GAS DETECTOR SOURCE SHUPTEAR SAMPLE = a | > cS ~ ~ 2 > i SYNCHRONOUS FILTER AH y PLIFIER RECELFLER =F ! | | ! STHICHRONOUS SPREDOMAR MOTOR RECORDER Figure 13. Block diagram of apparatus fer measurement of total absorption of infrared radiatién. se eet cegee! cS a i et i “exeydeo SoG SAS t Sacer onl