320 



Tables 390-391. 



THERMOELECTRIC PROPERTIES: PRESSURE EFFECTS- 

 TABLE 390. — Thermoelectric Power; Pressure Effects. 



The following values of the thermoelectric powers under various pressures are taken from Bridgman, Pr. Am. Acad. 

 Arts and Sc. 53, p. 269, 1018. A positive emf means that the current at the hot junction flows from the uncompressed 

 to the compressed metal. The cold junction is always at 0° C. The last two columns give the constants in the 

 equation E = thermoelectric force against lead (0° to 100° C) = (Al + BP) X io"» volts, at atmospheric pressure, a 

 positive emf meaning that the current flows from lead to the metal under consideration at the hot junction. 



Metal. 



Bit 



Zn t 



Tl t 



Cd t 



Constantant. 



Pd* 



Pt* 



W X 



Ni* 



Ag* 



§Fet 



Pb t 



Au* 



Cu t 



§ Al t 



§ Mo t 



§Snt 



Manganin t. 



Mgt 



Cot 



Thermo-electric force, volts X 10' 



Pressure, kg/cm' 



8000 I 



Temperature, ° C 



5 3. 000 



6,200 



4,930 



2,040 



2,850 



2,190 



1,810 



1,190 



700 



840 



, 30° 



460 



456 



+292 



-70 



+93 



+38 



— 123 



-84 



-156 



710,000 

 87,400 

 52,460 

 45,560 

 35,470 



26,520 



21,570 

 15.140 



11,440 

 10,560 



7,680 

 6,330 

 5,760 

 3,546 



1,962 



833 



+390 

 -1,314 



— 1,296 



— 2,061 



Formula 

 coefficients. 



-74.42 



+3 • 047 



+1.659 



+12.002 



-34- 76 



-5.496 



- 3092 

 + 1-594 



— 17.61 

 + 2.556 



+16.18 



+2.899 



+2.777 

 —0.416 

 +5892 

 +0. 230 

 +1.366 

 -0.095 

 -17-32 



+ .0160 

 -.00495 



— .00134 I 

 + .1619 

 -0397 



— .01760 

 -- 01334 

 + .01705 

 -.0178 

 + .00432 

 -.00892 



+ . 00467 ' 

 + - 00483 

 + . 00008 * 

 -j-. 02167 ^ 

 — . 00067 

 + .000414" 

 + . 00004 

 -.0390 I 



* Identical wire of Table 398. t Another wire of same sample, t Different sample. 

 § Results too irregular for interpolation for values at other temperature and pressures; see original article, 

 (i) —.0556/3; (2) — .04S6/3, annealed ingot iron; (3) —.05166/^; (4) —.041/'; (5) — .otisfi; (6) — .04ii2<'. 



TABLE 391. — Peltier and Thomson Heats; Pressure Effects. 



The following data indicate the magnitude of the effect of pressure on the Peltier and Thomson heats. They refer 

 to the same samples as for the last table. The Peltier heat is considered positive if heat is absorbed by the positive 

 current from the surroundings on flowing from uncompressed to compressed metal. A positive d^E/dP means a larger 

 Thomson heat in the compressed metal, and the Thomson heat is itself considered positive if heat is absorbed by the 

 positive current in flowing from cold to hot metal. Same reference and notes as for preceding table. 



l.!ctd. 



§Bit 



§Znt 



§Tlt 



§ Cd t 



Constantan X. 



§Pd* 



§Pt* 



§V/} 



§ Ni * 



Ag* 



§Fct 



Pb I 



Au * 



Cu t 



§Alt 



§ Mo t 



§Snt 



§ Manganin t 



Mgt 



§Cot 



Peltier heat, 

 lo^ X Joules/coulomb. 



Pressure kg/cm^ 



Temperature ° C 



+ 1070 



+98 



+66 



+19 



+46 



+35 



+23 



+ 17 



+11 



+13 



— II 



+7 



+6 



+4 



— 2 

 + 1 



— I 



+412 

 +229 



+ 221 



+ 140 



+ 103 



+65 



+65 



+ 50 



+44 



+36 



+30 



+25 



+ 16 



+17 



+ 1 



+2 



—4 



-48 



-90 



Thomson heat, 

 10' X Joales/coulomb/° C 



Pressure kg/cm^ 



Temperature ° C 



+1130 



+41 



+38 



+109 



+5 



+3 



+49 



+8 



+9 



+4 



+79 



+2 



+4 



+4 



+6 



+1 



+6 



+1 



o 



-14 



♦ t t § Same significance as in preceding table. 



Smithsonian Tables. 



