ys 166 Ip —— bit. “Ke In Ip ny 2B Amp. TT + +} Gain * i 4 _| Diff. Amp. ae= 1 Gain I ‘BL fin it I 8 4 In Im Vx -_ — a 1 I M iffi. . [ rt] Amp. 8 4 In Tu M 4 —F] Gain = = Ke | Atten. x=l _| ~—sOOitf. Amp. Divider Vy Ig Ip Ine - 2inge vy 9° = lOvE “Wy M Gain = 1 2 Ip (10) j > TIPS, Ig In - 4in = I Im —B _ 2 In 8 "Ty Iy Attenuator “Ke In xm I, Ig Ip Ig Ip In - 41n = In iy - 4 fn Im In ir - 2In IM In TT - 7, 1 (oy)4 tM Ip Ip n Tu (choose 10m = n) Fia. 133.—Circuit diagram for providing a continuous reading of the mixing depth in the case of linear variation of pollutan with height. Three pyrheliometers at one wave band and one zenith distance are used. In (Fes), ee) , —MrQe)Odds 2 gy.(44) (L + Ly)? n Gaeserae, Ip(r2) To(A1) coefficient varies linearly with height. Figure 133 gives a cireuit diagram for providing a continuous reading of the mixing depth. Therefore, L Thus, H, the mixing layer depth is determined from measured quantities for the case when the extinction _ r+n,"* gl 5 9) and CONCLUDING REMARKS Vertical Distribution of Pollutants The preceding development is based on an atmos- LS” phere in which the pollutants are distributed in height either uniformlyor linearly. Under these conditions, it One must exercise care to see that the square root is taken of positive numbers only. 1/2 PtanH=at io, : + a$™” — 1a8" _a = — Si2 H= l 47 , = [— sin Work of other investigators has indicated that at Ig(1) fora) |" . a | n (Pee TACHA EFa(rr) Fy) [ aes Zo() | 1/2 -[n (esses) is possible to use pyrheliometers to determinethe thickness of the mixing layer. In every case, it was assumed that the instruments measuring solar radiation were on an equatorial mount and, therefore, pointing at the sun. All of the equipment discussed, including the equatorial mounts, is available commercially off the shelf. . (48) times the vertical distribution of pollutants may be exponential.” A development similar to that above for the exponential distribution has been carried out byJ. Gilroy and D. N. Eggenberger.® The question arises on howto determine the distribu- tion of pollutant concentration with height in order to