Huygens Institute - Royal Netherlands Academy of Arts and Sciences (KNAW)
Citation:
Cath, P.G. & H. Kamerlingh Onnes, On the measurement of very low temperatures. XXVII. Vapourpressures of hydrogen in the neighbourhood of the boiling point and between the boiling point and the
critical temperature, in:
KNAW, Proceedings, 20 II, 1918, Amsterdam, 1918, pp. 1155-1159
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Physics. - "On the measurement of 1)el',1/ Zow tempemtuJ'es. XXVII.
V(t]Jour-pnJSsUJ'e8 of hyd1'ogen in the neigMoul'hood of the
boiling point and between the hoiling lJoint and the critical
,
< ,
tempe}·flt~t1'e".
(Oontinued). By P. G. OATH and hl. KAMERl.lNGH
Communication N°. 152a from the Physical Labol'atory
at Leiden.
ONNES.
(Communicated in the meeting of September 29, J917).
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§ 4. Results. Th!3 ,fo!l,?wing taP.1e gives a summa'')' of tlre ,'esults
obtained, Tht' tempel'utlll'es have, been rednced tb the absolute &cale
using tlle COl'l'ectlOns which are dednced f,'om thè Leiden determination of the compl'essibiiity of heli nm 1). Our thanks are due to
l
TABLE J. )
-
Vapour pressure of hydrogen
between its boiling point and critical temperature.
Nr.
0
I
I
0
T
0
t:,T
I P (in cms) I- p (in atm.) I (calc.-obs.)
24.59 K.
219.92
2.8931
+0.05
241.48
25.61
267.99
3.5262
-0.04
III
246.65
26.44
319.80
4.2080
+0.02
IV
245.87
21.22
370.65
4.8710
+0.02
V
245.80
27.29
376.30
4.9524
+0.03
VI
245.68
21.41
384.32
5.0566
+0.02
VII
244.;10
28.39
415.46
6.2561
+0.25
VIII
243.22
29.87
601.52
1.9148
+0.17
241.13
31.36
748.42
9.8416
+0.05
241.07
32.02
822.6
10.825
240.49
32.60
893.1
11. 752
-240.16
32.93
936.4
12.322
I
-248.50K.
11
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,
'IX
11
I
L
+0.03
+0.01
,
0.00
1
1) Leiden Comm.
I
N'I. l02b. These Proceedings. X, p. 589.
so
Ploc.cedlllgs Royal AL:lJ. AmsLcrJ<.l1ll Vol X X.
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III
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Mr. J. M. BURGERS for the care bestowed on the regulation of the
temperatnres.
The pressUl'es 1) are given in intel'national ems mercury of 0 0 C.the reductlOTI of the mel'cury columns which wel'e read on the brass
scales being made with 0.000163 as the coefticient of expansion and in international atmosphel'es respectively, the international atmosphere at Leiden being taken equal to 75.9488 ems mercllry at 00 C.
The table also cOlltains the results in the neighbourhood of the critical
poÏlit as found in Comm. N°. 151c.
As reg'al'ds the independence of the condensation-pressure from the
Cjnantity of hqllid condensed the following data may suffice:
TABLE 11.
1
I
0
I
p (in
atm.)
I
quantity
31.36 K.
9.8476
litUe Iiquid
31.35
9.8431
much Iiquid
21.22
4.8170
liUle liquid
21.22
4.8159
much Iiquid
~
These data refer to two determinations and the dilferenres observed
in both cases do not betJ~ay any systematic deviation in tbe dirertion
as would have to be expected, if the hydrogen were impure.
In the eepresentation of the observations by a formula we were
able to avaiI oursel ves of Professor V ImscHAFFELT~ kind assistanre,
who succeeded in obtaining a satisfactol'Y agreement with the obsel'vations by means of the relation
l' logp=-56.605+3.80151'-0 104587'~+0.003321Ta- 0.000051021 4•
(p being expressed in international atmospheres 2).
Tbe deviations l'educed- to degrees are larger, bowever, (esperially
in VII and VIII) than we bad a I'igbt to expect in view of the
arrangements of tbe measurements. As it concerns deviations not only
from the fOl'm 11 la, but from a smooth Cut've, we must assume in tbe
meantime that in VII and VIn some unexplained experimental
, error lies at the bottom of the disagreement.
.~
~ 5.
Detumination of the boiling ]Joint o} ltyrlJ'ogen. In order to
conneet our' detel'minatlOns to those ofComm. N°. 137d we have made
I
1I
,I
I) Leiden Comm. NO. 44:. These Proceedings. 1, p. 213.
2) According to this formula the cl'Ïtical pressure (at Tk
I
= 33°.18 K) is found
10 be 12.75 int. atm. In Comm. N°. J 51c 12.80 alm. was found.
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1157
two series or' detel'minations A and B using the same vapour-pressnre apparatus anel the same C'l'yostat as were used by KAl\flilRLINGH
ONNES and KEJ~Sal\[, B falling in lhe immediate neighbourhaod of
the boihng point. The results were as follaws:
,
TABLE lIl.
I
Vapour-pressure of hydrogen in the neighbourhood of the boiJing point.
INr.
(j
P tin ems) p (in alm.)
1
I
1
°
Al - 252.47
° K.
20.62
81.094
~
252 52
20.57
B2
252.59
B3
252.69
I
1.0670
- 0.01
80.336
1.0571
+ 0.01
20.50
78.532
1.0333
O.ÓO
20.40
-16.224
1.0030
0.00
20.39
76.000
1.0000
1 ONNES
ind KEESOM
0.00
I1
20.35
23.251
0.3059
0:00
16.93
15.36
11.402
0.1498
0.00
15 35
14.20
6 180
0.08132
72.876
0.9589
254.06
19.03
50.227
Aa
256.15
16.94
A4
257.73
As
258.89
1I
- I
19.01
20 21
iI
\
o 6609
252.88
1
,
KAME~LINGH
+ 0.04
+ 0.02
B4
A2
I
b.T
(ealc.-obs.)
1
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l~,
I
14~
+ 0.01
I
I
1
The two series A and B were made wlth two different heliumthermometers : the satisfactary agreement between the twa may be
taken as a guarantee of the aceuraey obtained.
The tifth column shows the deviatIOns from the fonnnia given in
§ 4 l'educed to degree&; the sixth column gives the meaSllrements
by KAl\mllUNGH ONNES alld KlmsoM of Oomm. N°. 137 cl corrected in a
mannel' whieh wiU be explained presently.
Fl'om t he data of Til bie IIT it follows by interpolation in the
table that tlle boilingpoint is T
20°.39 K. In Oomm. N°. 137d20° 33 K.
was founJ. T~ explain this diffet'ence we may utilize tlle reading of
the thel'mOmetel' Pt'J which, in these meaSllrements was placed in
the bath of liqnid hydrogen together with tlle vapom-pressme tube.
In tlle investigation by KAl\mRLINGH ONNES and KEFSOM, who determined tlle temperatlll'eb by means of Pt'J one of the readings gave
I
1111
I
I
I·KI
I,
I'
I
I
=
lJcoe.t
= 78,91 em.
HIpt!,
.lIl!
I·
I
= 1.928 .2,
whel'eas fl'om Ollr measurements we find by interpolation
pcoex
= 78,91 cm.
HTplI'
= l,9304.Q
80'*
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1158
111
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as 0.00115 ~~ cO/'l'esponds to 0.01 of a degl'ee, it follows that the
difference KAMERUNGH ON NES and KEESOM - CATH and KAMERJ.lNGH
ONNFS amoullts to only .02 of a degree 1). In this we approach the
probable error of the measurements.
In estimating the difference of the boiling point given in Comm.
N°. 137d with the \'alue now obtained by us, wé ha\'e to take into
account the following Clrcumstance: in Comm. N°. 137 cl the calibration
of Pt'l is carried out with a hydrogen-thermometer described in
Uomm. N°. 141a, whereas our measurements are based on the helium- ~
thet·mometer. Redncing this eahbration to the readings on the heliumI
thermometer which was in the same bath during the calibration of
the resistance in Oomm. N°. 141a, the temperatUl'es in the hydrogenrange (l'omp. Table I in Oomm. N°. 141a) have to be raised by .02 of a
degree. The val ne of 20.33 K found in 137 d has thus to be l'eplaced
by 20.35 K. All the vallles given b,v KAMERLJNGH ONNES and KlmsoM,
which are contained in column 6 of Table III ha\'e been corl'erted
in the same manner.
The difference of 0.04 of a degree which thus remams near the
boiling point is largel' than might have been experted in view of
the accllracy of the separate observations. With the exception of
I) In Comm. NO. 137d § 4, llote 2, p. 42. KAMERLINGH ONNES and KEESOM,
compare their measurements on the vapour pressure of hydrogen with those of
TRA. VERS and JACQUEROD. To this end KAMERLINGH ONNES and KEESOM recalculate the results which these observers obtamed with the aid of a hydrogen ther·
mometer [the most prominent is the boiling point ot' hydrogen, 20°22 from the
absolute zero on their hydrogen thermometer (20°.41 from the absolute zero on
their heliumlhermometer)] and make use to this end of the pressure co!!fficient of
hydrogen 0,0036628 for the international hydrogen thermometer of 1000 mmo
pressure at 0° C, and of the correction to the KELvIN-scale according to § 2 of
Comm. NU. 137d fOl the pressure of 953 mmo at 0° è. An error having been
found by KAMERLINGH ONNES and KEESOM in their recalculation we give here the
table as it ought to be according to them; introducing at the same tIme in the
second column of it the correct ion which we applied 10 the observaLioJls of K. O.
and K. in table III ahove.
~nternat. cm
of mercury
T KELVJN-Scale •
K. O. and K.
0
T KELVJN-Scale
(T and I)
°
76
20.35 K.
20.40 K.
35
17.98
17.97
10
15.09
15.14
--
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(Note added in thc translationl.
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this diffel'ence at the boiling point the devialiolls which remaill
between our investigation and th at of 137d are none of them mOl'e
than 0.01 of a degree and 0.02 of a degree. It.seems that the deviation
at the boiling point consists of two pal'ts, viz. the deviation of 0.02 of a
degree in the determination of the pressure of hydl'ogen with the
same reading of the platinum thermometer Pt 1 (or others whirh give
the same result) alld anothel' deviation also of 0.02 of a degree in
the calibration of the platinum therlllometer. It is thel'efore quite
possible that accidentally in the case of the boiling point an unfavourable roncurrenre of circumstances has prodllced a deviation whiclt
is largel' than the probable en'or. In our series of measurements a
deviation of 0.04 of a degl'ee from the smooth curve appears to
occn!' at B.; this reading must therefore be looked upon as suspect
and as possihly containillg an experimental el'l'or.
Taking into account the observation made at the end of § 4
it seems as if in the meantime the obSel'vatIOns VII and VIII of
Table I, the one by KAMERLINGH ONNES and KImsoM at 789,1 (the
value obtained fol', 76Q by intrapolation is mainly based on this
observation) and B4 lil Table III ha·va to be l'ejected, A renewed
set of meaSUl'ements over the whole range remains desIrabie in order
to arrh'e at the complete accmacy which the determination of the
tempel'atUl'es allows us to reach at present.
11
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1111
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