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Compilation of the Melting Points

Of the Metal Oxides

DISCARDED 3Y

M.5/D. A

U.S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
THE NATIONAL BUREAU OF STANDARDS

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Documents, Government Printing Office, Washington, D.C., 20402.
UNITED STATES DEPARTMENT OF COMMERCE • Luther H. Hodges, Secretary

NATIONAL BUREAU OF STANDARDS • A. V. Astin, Director

Compilation of the Melting Points

of the Metal Oxides

Samuel J. Schneider

National Bureau of Standards Monograph 68

Issued October 10, 1963

For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C., 20402 - Price 25 cents
Library of Congress Catalog Card Number: 63-60078
Compilation of the Melting Points of the Metal Oxides

Samuel J. Schneider

A compilation has been made of the melting points of 70 metal oxides published prior

to January 1963. Both the original melting point and the equivalent value based on the

International Practical Temperature Scale of 1948 are presented. Included in the survey

is information on pertinent experimental details such as the method of temperature measurement, purity, furnace type, and environmental conditions. The melting points of the metal oxides are perhaps one of the most studied but least known

of the physical properties. Seldom have two

investigators completely agreed upon a single

melting point value for a specific oxide. Many

reported values were derived from excellent

research and are quite reliable. Others are obviously in gross error. The result of this general

disagreement has been that over the years a myriad

of melting point values has been perpetuated

through the literature. To complicate matters,

necessary conversion from one temperature scale 1 to another has led to incorrect reporting of original

data. Furthermore, various compilations of criti- cal data have listed "best values" for the melting

points of the metal oxides which often have been

misinterpreted as unquestionably accurate and

valid. At the present time our knowledge of the

true melting points of the oxides can be regarded

as in no less than a state of utter confusion.

The National Bureau of Standards has recently

initiated a program of reevaluation of the melting

points of the metal oxides. The program tentatively includes the acceptance of previously

published values after experimental verification

as well as accurate determinations of ill-defined or completely unknown melting points. The

ultimate goal of the work is to have national and

perhaps international recognition of the melting

points of several specific oxides for use as calibration standards.

The initial effort in this program has been

placed in making a comprehensive literature

survey of previously published melting points of

the various oxides. The results of this compilation of data are presented in table 1. The information given in table 1 was taken from the original

published papers whenever possible. General

surveys [1, 2, 3, 4] 2 are referred to only when the

original source could not be established. Five

primary sources [5, 6, 7, 8, 9] were used initially to obtain a bibliography of papers dealing with

oxide melting point determinations. Reference

to these papers in turn yielded another bibliography of reports which again supplied additional

literature sources. The entire process was re- peated until no new references were obtained.

Through this cascading method of obtaining

references it is believed that a majority of all

1 Temperature scale refers not to the symbols denoting temperature ("K, °C, and °F) but to an actual scale with defining fixed points and formulas

for interpolating between such points.

2 Figures in brackets indicate the literature references at the end of this Monograph.

published data on oxide melting points up to January 1963 is included in the present work.

The oxides given in table 1 are arranged alphabetically according to the chemical symbol of the

metal element. Excluded from consideration are oxides which are not solids at room temperature.

Only oxides having stoichiometric metal to oxygen ratios are fisted. Identifying symbols such

as mineral names, crystal symmetry, etc., are given only to those oxides which are known to have polymorphs that melt metastably. In in- stances where an oxide has more than one reported

melting point, individual values are given in the

order of increasing magnitude according to the

value based on the International Practical Temperature Scale of 1948 (Text Revision of 1960)

Several criteria must be carefully considered in

obtaining accurate melting point data. These

factors in a general way are reflected by the

column headings of table 1. Because of the wide

divergence of melting point values, it is believed

worthwhile, and in order, to discuss briefly each

of these criteria more than normally would seem

warranted in a compilation of data.

Purity. The ultimate accuracy with which

any melting point can be determined is directly

associated with the purity of the material. It would seem that this fact need not be emphasized

however, reports are frequently found in the lit- erature in which purity was not considered or even mentioned. Terms such as "chemically

pure," "pure," and "reagent grade" are generally

meaningless unless specifically defined. Reasonable estimates of the percentages and types of

impurities must be known along with their possible effect upon the melting point. Sufficient

attention also must be given to the effects of

contamination of the sample by its container

during actual experimentation.

Furnace type. For obvious reasons it is particularly important in determining melting points

to insure against thermal gradients throughout

the sample as well as between the sample and

adjacent areas where actual temperature measure- ments are made. Uniformity of temperature can be completely assured only by the attainment of

blackbody conditions, which, of course, can never be entirely realized in practice. Excellent papers

by Gouffe [11] and by De Voss [12] give methods

for estimating the effective spectral emittance of

several types of enclosures and cavities. Resistance-type furnaces such as the wirewound quench or tube furnace can be constructed

1
so as to have small gradients between the specimen

and thermoelement. However, because of the

close proximity of the specimen and thermoelement

the deleterious effect of a gradient is usually

negligible.

Whenever radiation pyrometry is employed for temperature measurements, near-blackbody conditions are considered to be a necessity. The

induction furnace is generally one of the most

suitable for approximating blackbody conditions.

Temperature uniformity, with corresponding high

emittance, is easily obtained through the use of

inductively heated crucibles and cylinders.

Another furnace frequently used for high-temperature application is the strip furnace. It usually consists of a narrow, short strip of refractory metal sometimes necked down at its center

to provide a high-resistance area. Power is supplied to the strip through water-cooled leads. To facilitate temperature measurements, the strip

is generally made into the shape of a V (or U).

Specimens are generally placed at the apex of the

V or at the midportion of a flat strip. Temperature measurements are made on areas immediately

adjacent to the specimen.

The strip furnace provides an easy effective means of attaining high temperatures; however,

it is not particularly conducive to accurate

melting point determinations. Inherent with

this furnace are the inevitable extreme thermal

gradients throughout the specimen and area of

measurement. Tungsten strip lamps used for

calibration of optical pyrometers, although not

strictly comparable, have thermal gradients along

the filament which may amount to as much as

5 °C per millimeter [13]. Placement of a specimen on the strip will, in all probability, seriously

alter the thermal gradient of the bare strip. The

magnitude of this change will vary, depending

upon such factors as the location, volume, thermal

conductivity, and emissivity of the specimen.

It is a generally false assumption to consider

that a V-shaped metal strip approximates a blackbody enclosure. As long as there is any deviation

from isothermal conditions about the enclosure,

blackbody conditions cannot be realized.

However, brightness temperatures can approach

true temperatures if the emittance of the strip

is near unity. The use of a substance having a high natural emittance (i.e., graphite) as strip

material is not always feasible. Temperature measurement. The theory, use, and calibration of various temperature-measuring

devices have been well documented [13, 14, 15, 16]. The optical pyrometer or thermocouple is only one part of an entire temperature-measuring

system. Often, little attention has been given to the effect of auxiliary equipment or associated

apparatus on temperature measurements. An

inadequate reference junction of a thermocouple

circuit can cause errors as serious as those produced

by thermal gradients in a furnace. The effect of

stray or induced voltage from furnace windings

or other power sources can be very harmful and

yet go undetected.

The position of windows or enclosures relative

to the target area is extremely important in

making brightness temperature measurements

with an optical pyrometer. Gross errors arc produced by the reflection of radiation by the

windows, enclosures, or associated pieces into the

field of view of the pyrometer. Indiscriminate

use of published spectral emissivity values to convert brightness temperatures to true temperatures should be avoided. Emissivity refers to a

property of an opaque material whose surface

has been polished optically flat. Unless the target area of the pyrometer conforms to these conditions,

errors will result. The emittance of any enclosure

supposedly built as a blackbody is extremely

dependent upon the nature of internal reflections.

Even an enclosure in which the geometric design

is suitable 3 can have low emittance if the internal

reflections are predominantly specular rather

than diffuse [12, 13]. Method. It is not uncommon to observe that

oxides appear to melt over a range of temperatures

with a marked hysteresis between the apparent

melting and freezing points. The magnitude of

the hysteresis may vary from negligible quantities

to many degrees. Whatever the reason for the

hysteresis, whether it be partial dissociation, influ- ence of impurities, or other causes, the melting

point must be defined with respect to experimental conditions. The melting point of an

oxide can be specified as that temperature at which solid and liquid are in equilibrium for a given confining pressure and for given partial

pressures of environmental gases. Obvious difficulties are inherent in establishing

the melting temperature. Experimentally it can be taken as the temperature at which the last solid disappears on heating at a sufficiently slow

rate to insure temperature uniformity. Conversely, the freezing point is the temperature at which crystallization first begins. Dynamic

methods such as differential thermal analysis and

heating or cooling curves have the advantage of

the utilization of heat effects but the distinct

disadvantage of being rate-dependent. Cooling curve methods have been successfully applied

in the determination of the freezing points of

palladium, platinum, rhodium, and iridium (secondary reference points on the International

Temperature Scale of 1948 [10]). Pronounced

supercooling and superheating tendencies of many

oxides make this method somewhat less applicable,

although it may be the best available.

The method of visual observation of a specimen

during heating is generally unacceptable as an

accurate means of establishing the melting point.

If the specimen is visible, it is quite probable that

thermal gradients are present, thereby preventing

' A large ratio of interna] area of cavity to area of opening is required. The

ratio is sometimes expressed in terms of depth of cavity and diameter of

opening.

2
accurate temperature measurements. The attainment of blackbodv conditions renders the visual

method ineffectual, inasmuch as the specimen

would be indistinguishable from adjacent areas. The static method in which a specimen is heated

and cooled prior to examination has proved

satisfactory in many instances. Temperature

measurement is not as much a problem as with

dynamic methods. Auxiliary equipment such as the microscope and X-ray diffraction can be

readily applied to aid in determining the degree

of melting.

Calibration points. The determination of a melting point can be only thought of as being

obtained through the use of an integral system of various types of equipment and procedures. The

mere use of previously calibrated thermocouples

and pyrometers does not insure accurate measure- ment of temperature. It is highly desirable to

calibrate the entire system against the known

melting points of several standards. Insofar as

possible, the overall characteristics of the standards should conform to those of the test material.

Because of the present lack of recognized standards, calibration materials should generally be

limited to those defining the International Practical Temperature Scale [10]. It is as undesirable

to use substances having ill-defined melting points

as it is to use standards which have different

characteristics than those of the test material.

Environment. The effect of environmental gas

as well as the confining pressure on the melting

points of oxides has been generally disregarded

or considered noninfluential. Extensive studies

have been made only on those oxides (i.e., iron

and manganese oxides) which are pronouncedly

affected. It is conceivable that most oxides are

distinctly influenced by various gas partial pres- sures more than previously realized and partial

dissociation always occurs to some degree. If dissociation exists, an oxide can be expected to melt incongruently.

Melting point and temperature scale. Sosman

[17], in his paper "Temperature Scales and Silicate

Research," has extensively discussed the development of temperature scales, especially during the

period 1907 to 1948. In essence, a single scale

had not been recognized until about 1910 to 1914,

when the Geophysical Temperature Scale [18] was established. In 1927, the first internationally

recognized scale [19] was adopted. A major revision of the 1927 scale was made in 1948 [20], with

subsequent text revision in 1960 [10]. Some of the

principal fixed and secondary reference points of the three scales are given in table 2. The Geophysical Scale is, for consistency of data, still being

used by a few investigators. The 1948 scale has

entirely superseded the 1927 scale as being a closer approach to the thermodynamic scale. Numerical

differences between the three scales generally

amount to less than one degree at temperatures

below the gold point. At higher temperatures,

the variance becomes much greater. The GeoTable 2. Some fixed and secondary points of the geophysical

and international temperature scales

Material

Property a Int. 1927

[19]

Int. 1948

[10]

Geophvsical

[17]

°C °c °C

Naphthalene B.P. 217. 96 218. 0 217. 95 Tin M.P. 231. 85 231. 91 231'. 9 Benzophenone B.P. 305. 9 305. 9 305. 9 Cadmium M.P. 320. 9 321. 03 320. 9 Lead M.P. 327. 3 327. 3

Zinc M.P. 419. 45 419. 505 419. 4

Sulfur B.P. 444, 6 444. 6 444 5 5 Antimony M.P. 630. 5 630. 5 630. 0

Silver M.P. 960. 5 960. 8 960. 2 Gold M.P. 1063 1063 1062. 6 Copper M.P. 1083 1083 1082. 8 Diopside M.P. 1391. 5 Nickel M.P. 1453 1452. 4 Pallauium M.P. 1555 1552 1549. 5 Platinum M.P. 1769 1755 Rhodium M.P. 1960

Iridium M.P. 2443 Tungsten. M.P. 3400 3380

» The symbols B.P. and M.P. roughly signify boiling point and melting

point, respectively. For exact designation of the property under consideration, reference sho"uld be made to the appropriate publication.

physical Scale has an upper limit at the melting

point of platinum, defined as 1755 °C. Approximate differences between the Geophysical and 1948

scales at various temperatures can be obtained

from appropriate plots of the data given in

table 2. The 1927 scale above the gold point

is based on the Wien radiation formula,4 which is not strictly valid at extremely high temperatures.

The 1948 scale utilizes the Planck equation i for temperatures above the gold point. The equation

is applicable to indefinitely high temperatures.

Conversion from the 1927 scale to the 1948

scale, above the gold point, can be accomplished

through the use of the foUowing equation as derived by Corruccini [21].

s

« (Wien)

l0g

' JZTT [l336~(S+273)] U)

If X«+273) is less than 0.3 cm deg the resulting error is less than 1 °C.

(Planck)

J, ^[xft^rj-1 m

esp [Mifn)]-'

where

Ja, and Ji=radiant energies per unit wavelength interval emitted per unit time by unit area of a blackbodv at temperature t and at the

gold point tAm. X=wavelength (approximately 0.65X10-* cm for most optical pyrometers) C5=second radiation constant=

1.432 cm deg (1927) or

1.438 cm deg (1948) ro=273.15 deg.

5 The equation is derived by equating the right side of eq (1) with the logarithm of the right side of eq (2), expressing in exponential form and substituting appropriate values for To, Ct, and t** (1063 °C).

3
exp

|~ 1.438

|_1336.15X

r

1.438

exp

L (T+273. 15) X

where

=exp ri^2 /_i i_\i

P

L X \1336 T'+273/J

X=wavelength (approximately 0.65 X 10 -4 cm for most optical pyrometers)

T=a temperature above the gold point, °C (Int.

1948)

T'=a temperature above the gold point, °C (Int.

1927).

Approximate conversion from other temperature scales in use prior to 1927 can be accomplished

in a similar manner. To ease calculations only

Wien's relationship is utilized. The resulting

equation necessary for the conversion is

1.438 T 1 X l_1336"

where

(T+273)]

A' L(W+273) (T'+273)]

CV =second radiation constant originally

employed

T=a temperature above the gold point,

°C (Int. 1948)

T'=& temperature above the gold point,

°C (original scale)

t iu '=go\d point originally employed (generally 1063 °C)

X and X'= wavelength (X and X' can be assumed

to be equal).

In the present work, all original melting points

have been converted, whenever possible, to values

based on the 1948 temperature scale by methods

previously described. Unfortunately, some published papers fail to state the temperature scale

utilized. Conversion to the 1948 scale was impossible in these instances unless the scale could be

unambiguously assumed from information such

as the date of publication or listed calibration

temperatures and radiation constant. Comments. Other than for the obvious purpose

of the compilation of critical data, the present

survey has another important function, in that it vividly illustrates the variance of melting point

values found in the literature. No attempt will be made for the present to select one value over another as being absolutely correct. It is quite

difficult to ascertain completely the validity of published data without additional experimental

work. However, it is believed appropriate to make pertinent comments about the less obvious

shortcomings inherent in any published work and

to designate the preferred values with an asterisk.

Many thanks are due to J. L. Waring for the

collection of many of the original papers and to Mrs. J. Marcus for her excellent partial translations of foreign articles. Without their help, this

publication would have been impossible.

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[76] C. E. Curtis, L. M. Donev, and J. R. Johnson, J. Am. Ceram. Soc. 37, 458-465 (1954).

[77] E. H. P. Cordfunke and G. Mever, Rec. Trav. Chim.

81, 495-504 (1962).

[78] J. White, D. D. Howat, and R. Hav, J. Roval Tech.

Coll. (Glasgow) 3, 231-240 (1933).

[79] H. J. Van Hook and M. L. Keith, Am. Mineralogist

43, 69-83 (1958).

[SO] T. Ranganathan, B. E. MaeKean, and A. Muan, J. Am. Ceram. Soc. 45, 279-281 (1962).

[81] T. CarneUev, J. Chem. Soc. (London) 33, 273-284

(1878).

[82] E. Groschuff, Z. Anorg. Chem. 58, 113-119 (1908).

[83] F. M. v. Jaeger and H. C. Germs, Z. Anorg. Allgem.

Chem. 190, 145-173 (1921).

[84] F. Hoermann, Z. Anorg. Allgem. Chem. 177, 145-186

(1929).

[85] G. D. Rieek, Rec. Trav. Chim. 62, 427-430 (1943).

[S6] L. A. Cosgrove and P. E. Snvder, J. Am. Chem.

Soc. 75, 1227-1228 (1953).

[87] G. Brauer, Z. Anorg. Allgem. Chem. 248, 1-31

(1941).

[88] M. W. Shafer and R. Rov, Z. Exist. 110, 241-248

(1958).

[89] M. Ibrahim, X. F. Bright, and J. F. Rowland, J. Am. Ceram. Soc. 45, 329-334 (1962).

[90] R. S. Roth and J. L. Waring, J. Research XBS 66A

(Phys. & Chem.), 451-463 (1962).

[91] A. Reisman and F. Holtzberg, J. Am. Chem. Soc. 77, 2115-2119 (1955).

[92] R. S. Roth and J. L. Waring, J. Research XBS 65A

(Phvs. & Chem.), 337-344 (1961).

[93] F. Holtzberg, A. Reisman, M. Berrv, and M. Berkenblit, J. Am. Chem. Soc. 79, 2039-2043 (1957).

[94] R. S. Roth and L. W. Coughanour, J. Research

XBS 55, 209-213 (1955).

[95] R. L. Orr, J. Am. Chem. Soc. 75, 2808-2809 (1953).

[96] P. D. Merica and R. G. Waltenberg, Tech. Pap. BS

19, 155-182 (1925).

[97] H. v. Wartenberg, Ann. Chem. Liebigs 440, 97-110

(1924).

[98] J. M. A. Hoeflake and M. F. C. Scheffer, Rec. Trav.

Chim., 45, 191-200 (1926).

[99] S. Hilpert and P. Weiller, Ber. Deut. Chem. Ges.

42, 2969-2977 (1909).

[100] R. Schenck and W. Rassbach, Ber. Deut, Chem.

Ges. 42, 2917-2925 (1908).

[101] R. F. Geller, A. S. Creamer, and E. X. Bunting, J. Research XBS 13, 237-244 (1934).

[102] K. A. Exakau, Ann. Secteur Anal. Phvsico. Chim.,

Inst, Chim. Gen. (USSR) 8, 331-350^(1936).

[103] V. A. Exoll, Z. Anorg. Chem. 78, 95-133 (1912).

[104] H. C. Cooper, L. I. Shaw, and X. E. Loomis, Ber. Deut, Chem. Ges. 42, 3991-3993 (1909).

[105] W. B. Hincke, J. Am. Chem. Soc. 52, 3869-3877

(1930).

[106] R. Wietzel, Z. Anorg. Allgem. Chem. 116, 71-95

(1921).

[107] K. Endell and R. Rieke, Z. Anorg. Chem. 79, 239-

359 (1913).

[108] J. B. Ferguson and H. E. Merwin, Am. J. Sci. (4th

ser.) 46, 417-426 (1918).

[109] J. W. Greig, Am. J. Sci. (5th ser.) 13, 1-44 (1927).

[110] X. Zhirnova, J. Gen. Chem. USSR 4, 1455-1470

(1934).

[Ill] V. J. Barczak and R. H. Inslev, J. Am. Ceram. Soc.

45, 144 (1962).

[112] A. Reisman, F. Holtzberg, M. Berkenblit, and M.

Berrv, J. Am. Chem. Soc. 78, 4514-4520 (1956).

[113] 0. Ruff, F. Ebert, and H. Woitinek, Z. Anorg.

Allgem. Chem. 180, 252-256 (1929).

[114] W. O. Statton, J. Chem. Phys. 19, 33-40 (1951).

[115] H. Sigurdson and S. S. Cole, J. Metals 1, 905-908

(1949).

[116] D. E. Rase and R. Rov, J. Am. Ceram. Soc. 38,

102-113 (1955).
[117] L. W. Coughanour and V. A. DeProsse, J. Research

NBS 51, 85-88 (1953).

[118] P.D.S. St. Pierre, J. Am. Ceram. Soc. 35, 188 (1952).

[119] S. M. Lang, C. L. Fillmore, and L. H. Maxwell, J. Research NBS 48, 298-312 (1952).

[120] G. Brauer and W. Littke, J. Inorg. Nucl. Chem. 16,

67-76 (1960).

[121] A.B.F. Duncan, J. Am. Chem. Soc. 51, 2697-2705

(1929).

[122] T. C. Ehlert and J. L. Margrave, J. Am. Ceram.

Soc, 41, 330 (1958).

[123] O. A. Cook, J. Am. Chem. Soc. 69, 331-333 (1947).

TABLE 1 i

Reference Purity Furnace type Temperature measurement Method

Kracek [3]...

Shun-icbiro Iijima [22]

Tiede and Birnbrauer

[23].

Geller and Yavorsky

[24].

Ruff and Lauschke

[25].

Weigel and Kaysser

[26].

Mark [27].

Diamond and

Schneider [28].

Geller and Bunting

[29].

Lambertson and

Gunzel [30].

Ruff [31]

Bunting [32].

McNally, Peters, and

Ribbe [33].

Ruff and Goecke [34]..

Lang, Knudsen, Fil- more, and Roth [35].

v. Wartenberg, Linde, and Junq [36].

Not stated

Not stated

Not stated

Three samples: (a) Soda

free, 0.05% carbon; (b) 0.01% impurities; (c) <0.01% each of seven

metals.

Commercially pure

Two samples: (a) Not

stated (b) Alkali free.

Not stated.

About 99.9%.

99.98?! -

99.5%.

Pure.

W.Kr [.

Not stated.

Not stated.

Pure.

Not stated

Not stated

Arc

Resistance; ThO*-Ce02

heating elements.

Resistance; graphite tube

heating element.

Resistance; graphite tube

heating element.

Resistance; graphite tube

heating element.

Not stated.

Not stated.

Solar.

Resistance.

Resistance; W heating

element.

Resistance; graphite tube

heating element.

Induction; Ir alloy susceptor, button-shaped.

Induction; graphite tube

susceptor.

Resistance; graphite tube

heating element.

Resistance; graphite tube

heating element.

Flame; oil-oxygen.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Optical pryometer sighted on

specimen. Specimen not

visible.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

small cavity in susceptor adjacent to specimen cavity.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

See footnotes at end of table.

Not stated

Weight loss measurements.

Observation of specimen during heating.

Observation of pyramidshaped specimen during

heating. Rounded corners indicated melting.

Observation of specimen during heating.

Observation of specimen during heating.

Observation of specimen during heating.

Observation of bar-shaped specimen during cooling.

Observation of specimen

during heating.

Examination of specimen

after heating.

Observation of specimen during heating.

Examination of specimen after heating.

Observation of specimen sus- pended in furnace during

heating.

Observation of cone-shaped specimen during heating. Fusion of cone tip indicated melting.

Observation of pyramidshaped specimen during

heating. Deformation of pyramid tip indicated melting.

Observation of specimen sus- pended in furnace during

heating.
[124] V. V. Illarionov, R. P. Ozeron, and E. V. Kil'- disheva, Zh. Neorgan. Khim. 1, 777-782 (1956).

[125] F. Holtzberg, A. Reisman, M. Berry, and M. Berkenblit, J. Am. Chem. Soc. 78, 1536-1540 (1956).

[126] C. McDaniel, NBS, personal communication.

[127] A. Burdese, Ann. Chim. (Rome) 47, 785-796 (1957).

[128] E. N. Bunting, J. Am. Ceram. Soc. 13, 5-10 (1930).

[129] E. Podszus, Z. Angew. Chem. 30, 17-19 (1917).

[130] S. J. Schneider, J. Am. Ceram. Soc. 43, No. 7, 354-

355 (1963).

[131] G. Gattowand H. Schroder, Z. Anorg. AUgem. Chem.

318, 176-189 (1962).

Calibration Points

Materials Temp.

Environment Original Temp.

Scale 3

Melting Points

Original Int. 1948 <

Comments

Not stated.

Not stated.

Not stated.

60PM0Rh..__

80Pt-20Rh_...

90Pt-10Rh_...

lOOPt —

Au._. CaF2 -

Ag.. Au.

Pd_

Pt„

Rh.

Ir...

Not stated.

None.

Pt

90Pt-10RhPt.

Pt.

Not stated.

AI2O3-

Au.

Pt.

AI2O3 BeO.

Pt.. Mo.

1940-

1905

1845

1773.5

1062.4. 1398...

960.5. 1063 1557-

1770-

1970-

2415

Not stated. Not stated

(1769).

1755.

2044.

1071.

1757

2035. 2510

Not stated. Not stated

Not stated.

Not stated.

Vacuum

Not stated.

(Int. 1927)..

°C

191 dissociates.

Not stated.

230 dissociates...

1890.

230.

(Air). Int. 1927- 2000 to 2030.

(a) Air at 7.5 mm Hg_

(b) Air at 7.7 mm Hg_

(al) Nitrogen atm

(a2) Air

(bl) Reducing

(b2) Air

C2=1.437 cm

deg

C2=1.44 cm deg

(a) 2005..

(b) 2008.

Neutral. (Int. 1948).

(al) 2007±4_

(a2) 2010---.

(bl) 2001—-

(b2) 2005 to 2010

2020-

Air. Int. 1948. 2025.

Air. Int. 1927. 2035 ±10.

Helium. (Int. 1948). 2034 ±16.

Not stated. C2=1.46 cm deg. 2010 ±10.

(Air). Int. 1927. 2045 ±25.

Air, argon, nitrogen..

Nitrogen.

Int. 1948. 2043 ±10.

(C2 =1.48cm

deg).

2020.

Argon. Int. 1948. 2049_

Air. (Int, 1927). 2055-

1994 to 2024.

2005. 2008

2009±4

2012

2003

2007 to 2012

2020.

2025-

2029 ±10.

2034 ±16.

2035 ±10.

2038 ± 25.

2043 ±10.

2044.

2049.

2049.

Survey; not original data.

5

; partial dissociation probably

occurred.

(5)

s

; partial dissociation probably

occurred; reaction between

specimen and graphite support probable.

5

; reaction between specimen and charcoal support probable.

5

; reflection errors possible.

6

; emissivity stated by authors

to be about unity.

5

; reflection errors possible

5

; reaction between specimen and

graphite support probable.

Temperature uniformity be- tween specimen and target area of pyrometer not verified.

(t)-

8

; reaction between specimen and graphite support probable.

(»)-

(«)-

G90165—63 2 7
TABLE 11

Reference Purity » Furnace type Temperature measurement Method

Kanolt [37].

Smits and Beljaar [38]

Welch and Duschak

[39].

Rushton and Daniels

[40].

Kracek, Morey, and Merwin [41].

McCulloch [42].

Schumacher [43].

Tiede and Birnbrauer

[23].

Ruff and Lauschke

[25].

Lang, Knudsen, Fil- more, and Roth

[35].

v. Wartenberg,

Reusch, and Saran

[44].

v. Wartenberg and Werth [45].

Ol'Shanskil [46]

Ruff [31].

Belladen [47].

Fe—0.001% Cu—none

Si Ot—0.001%

Chloride—0.005% Sulfate—0.001%

Not stated.

C. P. grade.

Not stated.

100 ± 0.1%-

99.6%.

Not stated.

Not stated.

Pure.

99.9+%.

Commercially pure.

Commercially pure.

Not stated.

Pure.

Not stated.

Gattow and Schroder

[131] 100±0.1%

Resistance; graphite tube

heating element.

NaN03-NaNOa bath.

Not stated.

Resistance; iron pot heat- ing element.

Resistance; quench type, wire-wound ceramic tube heating element.

Not stated.

Resistance; boat-shaped W strip heating element.

Arc.

Resistance; graphite tube

heating element.

Resistance; graphite tube

heating element.

Flame; gas-oxygen.

(Flame); "ZrOjoven''

Resistance; quench type, graphite tube heating

element.

Resistance; carbon tube

heating element.

Resistance

Not stated.

Optical pyrometer sighted on

blackbody cavity immersed

in specimen.

Pt resistance thermometer.

Copper-constantan thermocouple.

Copper-constantan thermocouple.

Thermocouple.

Not stated.

Optical pyrometer sighted on W strip adjacent to speci- men. Spectral emissivity equals 0.431.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer.

Optical pyrometer.

Optical pyrometer sighted on

hole in side of heating

element.

Optical pyrometer sighted on

specimen.

Pt-PtRh thermocouple im- mersed in specimen.

Pt-PtRh thermocouple im- mersed in specimen.

Thermal analysis, heating

curves.

Intersection of vapor pressure

curve.

Thermal analysis, heating

curves; also examination

of specimen after heating.

Intersection of vapor pressure

curves.

Examination with microscope

of quenched specimen after heating. Last trace of crystals indicated melting point.

Observation of specimen during heating.

Observation of specimen during heating.

Observation of specimen during heating.

Observation of specimen during heating.

Observation of pyramid

shaped specimen during

heating. Deformation of pyramid tip indicated

melting.

Observation of specimen

during heating. Rounded

corners of suspended speci- men indicated melting.

Not stated.

Examination of quenched

specimen after heating. Formation of round balls indicated melting.

Observation of specimen during heating.

Thermal analysis, cooling

curves.

Thermal analysis, cooling

curves.

See footnotes at end of table.
-—Continued

Calibration Points

Materials Temp.

Environment Original Temp.

Scale 3

Melting Points

Original Int. 1948 «

Comments Oxide

Sb. 630-

Cu-Ag

eutectic. Ag

Cu

Diopside.. Pt

779..

960.5 1083

1391

1755

Not stated.

Water

Naphthalene

Benzophenone.

Not stated—.

Not stated.

Not stated—

Not stated.

Not stated.

Au...

CaFj.

AljOs. BeO_.

1062.4. 1398

2035. 2510

Not stated.

Not stated.

Not stated.

Pt.

Not stated.

Not stated.

1755.

(a) Vacuum at 2 mm

Hg.

(b) Hydrogen —

6.1 mm Hg.

(100 °C) Not stated. Not stated Not stated

Not stated.

Not stated

(Air).

Not stated.

Hydrogen at 0.2 atmospheres.

Vacuum.

Air at 15 mm Hg.

Argon.

Oxidizing.

Oxidizing.

Nitrogen.

Nitrogen at 4 to 10 mm Hg.

Not stated

(Air).

(Int. 1927).

Not stated.

Not stated.

( Geophysical). .

Not stated.

"C

2050.

312.3 Triple point.

313.

315.

450±2.

Ci= 1.433 cm

Not stated.

Cj=1.437 cm

Int. 1948..

(Int. 1927).

(Int. 1927).

(Int. 1948).

C2=1.46 cm deg.

Not stated.

(Int. 1948) .

460 to 470.

1923.

2400 ± 100.

2410.

2452.

2520±30.

2570.

2570 ±30.

2525-

817.

824±2.

2072 '

312.3

'

450±2*

1918.

2452.

2508±30.

2557.

2570±30.

2573.

824±2.

Partial dissociation probably

occurred at reduced pressure. AI2O3—

Con.

Pressure at melting not stated; melting point should be desig- nated as triple point.

Pressure at melting not stated; melting point should be desig- nated as triple point.

Reaction between specimen and

SiOa container probable.

6

; temperature uniformity be- tween specimen and target area of pyrometer not verified; reflection errors probable.

(»)-

2410- __- t

; reaction between specimen and graphite support probable.

(

5)-

AS2O3 Monoclinic type.

B2O3

BaO

BeO

(«)-

Specimen dropped through heat- ed furnace; thermal lag be- tween specimen and measured

temperature probable.

Reaction between specimen and

graphite support probable.

Bi;02

9
TABLE 1 i

Reference Purity a Furnace type Temperature measurement Method

Guertler [48].

Levin and McDaniel

[49].

Schumacher [43].

Kanolt [37].

Ol'Shanskii [46].

Doman, Barr, McNally, and Alper

[50].

Roth [51]

Ruff [31].

v. Wartenberg and

Gurr [52].

Trombe [2]

v. Wartenberg,

Reusch, and Saran

[44].

v. Wartenberg and

Prophet [53].

v. Wartenberg and

Gurr [52].

Ruff [31].

Kanolt [37].

Not stated

Si and Fe<0.01%

Al and Pb<0.001%

Ag, Ca, Cr, Mg, and Mn

<0.0001%.

C.P. grade

Na and K—nil.. Mg—trace H2S metals—nil CI—0.004%

Sulfate—nil

Not stated

Not stated

Si—0.001 to 0.01%

Al, B, Ca, Cu, Fe, Mg

and Pb—0.0001 to 0.001% Ag—<0.0001%

Not stated

Not stated

Not stated

Ni Free .-.

99.9%.

Pure

Not stated..

Iron—0.01%.. Chromate—trace Sulphate—0.005%.

See footnotes at end of table.

Not stated.

Resistance; quench type, Pt alloy wire-wound

ceramic tube heating

element.

Resistance; boat-shaped W strip heating element.

Resistance; graphite tube

heating element.

Resistance; quench type, graphite tube heating element.

Not stated.

Resistance; quench type, Pt alloy wire-wound

ceramic tube heating element.

Resistance; carbon tube

heating element.

Flame; acetylene-Oj

Not stated.

Flame; oil.

Flame; oxyhydrogen or

gas-air.

Not stated.

Resistance; carbon tube

heating element.

Resistance; graphite tube

heating element.

Thermocouple immersed in specimen.

Pt-90Ptl0Rh thermocouple

adjacent to specimen.

Optical pyrometer sighted on W strip adjacent to speci- men; spectral emissivity equals 0.418.

Optical pyrometer sighted on

blackbody cavity immersed

in specimen. Also, speci- men acted as blackbody

enclosure.

Optical pyrometer sighted on

hole in side of heating ele- ment.

Not stated.

Pt-90Ptl0Rh thermocouple

adjacent to specimen.

Optical pyrometer sighted on

specimen.

Not stated.

Not stated.

Optical pyrometer sighted on

specimen.

Optical pyrometer.

Optical pyrometerOptical pyrometer sighted on

specimen.

Optical pyrometer sighted on

blackbody cavity immersed

in specimen.

Thermal analysis, cooling curves.

Examination with microscope

of quenched specimen after heating.

Observation of specimen during heating.

Thermal analysis, heating

curves.

Examination of quenched

specimen after heating. Formation of round balls indicated melting.

Not stated

Examination of quenched

specimen after heating.

Observation of specimen during heating.

Observation of specimen during heating.

Not stated

Observation of specimen sus- pended in furnace during

heat. Rounded corners in- dicated melting.

Not stated

Not statedObservation of specimen during heating.

Thermal analysis, heating

curves.

10
—Continued

Calibration Points

Materials Temp.

Environment Original Temp.

Scale 3

Melting Points

Original Int. 1948 *

Comments Oxide

Not stated.

NaCL

Au...

Not stated.

SbCu-Ag

Euteetie. AgCu

Diopside.. Pt

Not stated.

Not stated.

Not stated.

Pt.

Not stated.

Not stated.

Not stated.

Not stated.

Not stated.

Pt.

SbCu-Ag

Eutectic. AgCu

Diopside -

Pt

800.4. 1063

630. 779

1083

1391 1755

1755.

1755-

630... 779

960.5 1083

1391

1755

Not stated. Not stated.

Air. Int. 1948.

Hydrogen at 0.2 atm..

Hydrogen.

Nitrogen.

Not stated.

Not stated.

Not stated.

Air.

Not stated .

Oxidizing.

Air.

Nitrogen at

(a) 30 mm Hg

(b) 1 atmosphere.

Vacuum

C2 =1.433 cm

deg.

TO

(Int. 1948)

(Int. 1948).

Int. 1948.

Cj=1.46 cm

deg.

(Int. 1927).

Not stated

ant. 1927).

ant. 1927).

(Int. 1927).

820±2_.

825±3.

2576.

2572.

2620.

2630.

>1500.

1950.

>2600.

2800.

1800±20.

1810.

1935.

825±3*

2565.

2614*

2620.

2630.

>1500.

1973.

>2600

1795±20.

1805.

1929.

Cj=1.46 cm deg.

(•).

(a) 1830 to 2080..

(b) 1960

1990.

1849 io 2107. 1983

2011.

Bi20a—

Con.

5

; temperature uniformity be- tween specimen and target area of pyrometer not verified; reflection errors probable.

CaO

Specimen dropped through

heated furnace; thermal lag between specimen and measured temperature probable.

Melting point taken from abstract.

Author noted that CdO sub- limes rapidly.

Reaction between specimen and

ZrOz support probable.

CdO

CeOj

Survey; not original data.

(»)- CoO

Oxidation state of cobalt not

investigated.

Authors stated this melting

point to be in error; see pre- ceding reference [53] for cor- rected value.

8

; reaction between specimen and graphite support probable. Author concluded re- duction of specimen occurred.

Oxidation state of chromium

not investigated. Reduction

is probable.

Cr2 03

11
TABLE 1 i

Reference Purity • Furnace type Temperature measurement Method

Wilde and Rees [54]...

Bunting [55]-

Bunting [32].

v. Wartenberg and

Reusch [56].

McNally, Peters, and

Ribbe [33].

v. Wartenberg and

Eckhardt [57].

Rengade [58].

Ruer and Nakamoto

[59j.

v. Wartenberg,

Reusch, and Saran

[44].

Roberts and Smyth

[60].

Wlsnyi and Pijanowskl [61].

Not stated . Resistance; graphite tube

heating element.

Induction; Ir alloy susceptor, button-shaped.

C. P. grade -

Analytical grade.

C03O4, SiOj, and V2O3-

0.01-0.1% AhOi, MgO, and FeaOs—

0.005-0.05% NiO—0.001-0.01% MnO and TiOj—1-10 ppm.

Induction; Ir susceptor, button-shaped.

(Flame) ;" Fletscher oven".

Induction; graphite tube

susceptor.

Not stated. Flame; acetylene-Oa.

Purified.

Not stated.

Flame-heated Al block

Resistance; carbon tube

heating element.

Pure. Flame; gas-oxygen.

0.0083% impurities. Not stated.

Not stated. Resistance; V-shaped W

strip heating element.

Photoelectric pyrometer

sighted on specimen.

Optical pyrometer sighted on

small cavity adjacent to specimen cavity.

Optical pyrometer sighted on

small cavity adjacent to specimen cavity.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Thermocouple.

Pt-PtRh thermocouple Im- mersed in specimen.

Optical pyrometer.

Pt-PtRh thermocouple.

Optical pyrometer sighted on

specimen.

Thermal analysis, heating

curves. Also, observation

of specimen during heating.

Examination of specimen after heating.

Examination of specimen after heating.

Observation of specimen sus- pended in furnace during

heating.

Observation of specimen sus- pended in furnace during

heating.

Observation of specimen sus- pended in furnace during

heating.

Thermal analysis, cooling curves. Also, observation

of specimen during heating.

Examination of specimen after heating.

Observation of specimen sus- pended in furnace during

heating.

Intersection of pressure-temperature-composition curves.

Observation of specimen during heating. Apparent dis- appearance of specimen

indicated melting.

Wisnyi and Pijan- owski [61].

Schneider [62].

Not stated.

Ba, Cu, Er, and Si- <0.01%;

Cr, Cu, Fe, Mg, and Ni-

<0.001%.

Resistance; V-shaped W

strip heating element.

Induction; crucible-shaped

Ir susceptor.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

small hole in crucible lid.

Observation of specimen during heating. Apparent dis- appearance of specimen

indicated melting.

Examination of specimen af' er heating. Flat button indi- cated melting.

See footnotes at end of table.
—Continued

Calibration Points

Materials Temp.

Environment Original Temp.

Scale 3

Melting Points

Original Int. 1948 *

Comments Oxide

AI1O3-

AI2O3.

"C

2040

2040.

Air..

(Air).

Not stated. (Air).

Pt. (1773). Air.

AI2O3- 2044. (a) Nitrogen.

(b) Air

Not stated.

Not stated. Nitrogen.

Cu. Ni_

Fe1084_ 1451

1528

Nitrogen..

Not stated- Oxidizing.

Quartz trans- formation AnNot stated

1062.6

(Int. 1927).—

(Int. 1927).

(Int. 1927).

(Int. 1927).

Int. 1948.

(Int. 1927).

Not stated.

Not stated.

(Int. 1927).

AI2O3- 2040.

0.6 mm Hg Pressure

Either helium, hydrogen, or vacuum.

Geophysical.

Int. 1948.

2060±25.

2140±25_

2275=1=25-

2275=1=25-

(a) 2315.

(b) 2330.

2435=1=10-

490±10.

1222.

1230±20.

1235.

2340=1=10-

AI2O3- 2040.

Au..

Pt... Rh..

1063- 1769 1960

Either helium, hydro- gen or vacuum.

Air.

Int. 1948. 2050±30.

Int. 1948. 2240±10.

2053 ±25.

2133±25.

2266±25-

2266±25.

2315- 2330

2424±10_

1222.

1229±20.

1236*

2340±10.

2050±30.

2240±10*

s

; reduction of specimen probable.

Temperature uniformity be- tween specimen and target area of pyrometer not verified. Bunting in later publication

[32] stated 2140 °C value is low

because of reduction during

calcine.

Temperature uniformity be- tween specimen and target area of pyrometer not verified. 0-

Cr2Oa—

Con.

5

; reduction of specimen is probable.

5

; reduction of specimen is probable.

Csa O

Cu2 0

(»).

» ; author's stated emissivity of approximately 0.9 to 0.95 is probably overestimated. Reflection error probable.

No melting point data located

in the literature.

5 ; author's stated emissivity of approximately 0.9 to 0.95 is probably over estimated.

Reflection errors and reduction in vacuum or hydrogen

probable.

Dy203

Er2 03

EU2O3

13
TABLE 1 i

Eeferenco Purity i Furnace type Temperature measurement Method

Chipman and Marshall [63].

Hay, Howat, and White [64].

Darken and Gurry

[65].

Bowen and Schairer

[66]

Moruzzi and Shafer

[67]

Darken and Gurry

[65]

Greig, Posnjak, Merwin, and Sosman

[68]

v. Wartenberg and

Eckhardt [57]

Hill, Roy, and

Osborn [69].

v. Wartenberg and

Reusch [56l.

Schneider and Waring [70]

Wisnyi and Pijanowski [61].

Fe and C—<0.005%; S <0.004%; Si<0.008%; Mn<0.003%; Cu<0.004 %; Cu<0.004%; P<

0.002%; Ni<0.031%.

Not stated..

Fe and C—0. 012%; Mn<0.01%; P—0.004%; S—0.003%; Cu—0.045%; Si—0.007%; Ni-O.02%; Pb—0.04%.

Not stated

High purity

Not stated.

FeaOs—99.7%; FeO—

0.03%; SiO2-0.01%; NaaO-0.04%; TiOi—

0.01%; MnO—0.01%; P2 Ot-O.005%

Commercially pure -

Not stated.

Not stated.

99.9%.

Not stated.

Resistance; SiC tube heating element.

Resistance; Mo wire- wound ceramic tube

heating element.

Resistance; quench type, Pt wire-wound ceramic tube heating element.

Resistance; quench type, Pt wire-wound ceramic tube heating element.

Resistance; quench type, Pt wire-wound ceramic tube heating element.

Resistance; quench type, Pt wire-wound ceramic tube heating element.

Resistance; quench type, Pt wire-wound ceramic tube heating element.

Flame; acetylene-oxygen

Resistance, U-shaped 60 Pt-40Rh strip heating element.

(Flame) "Fletscher

Oven".

(a) Induction; crucible- shaped Ir susceptor.

(b) Resistance; quench

type, Pt alloy wire- wound ceramic tube

heating element.

Resistance; V-shaped W

strip heating element.

Pt-90PtlORh thermocouple

adjacent to specimen.

Mo- Wthermoeouple adjacent

to the specimen.

Pt-PtRh thermocouple; temperature measured before and after each determination.

Pt-90PtlORh thermocouple; temperature measured before and after each determination.

Thermocouple adjacent to specimen.

Pt-PtRh thermocouple; temperature measured before and after each determination.

Pt-90PtlORh thermocouple

adjacent to specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer.

Optical pyrometer sighted on

specimen.

(a) Optical pyrometer sighted on small hole in crucible

lid.

(b) 95Pt5Rh-80Pt20Rh ther- mocouple adjacent to specimen.

Optical pyrometer sighted on

specimen.

Weight loss data; specimen

suspended from balance arm

Sudden weight loss indicated melting.

Differential thermal analysis..

Examination of specimen after heating.

Examination with microscope

of quenched specimen after heating.

Observation of rod-shaped specimen during heating. Rounded corners indicated melting.

Examination of specimen after heating. Formation of droplets indicated melting.

Examination with microscope

of quenched specimen after heating.

Observation of specimen sus- pended in furnace during

heating.

Examination with microscope

of specimen after heating.

Observation of specimen sus- pended in furnace during

heating.

(a) and (b) Examination of specimen after heating.

Observation of specimen during heating. Apparent dis- appearance of specimen in- dicated melting.

See footnotes at end of table.

14
—Continued

Calibration Points

Materials Temp.

Environment Original Temp.

Scale 3

Melting Points

Original Int. 1948 *

Comments Oxide

Cu. XL.

Pd.

Xot stated—

Not stated.

LijSiOj-.. Diopside. Pd

Xot stated.

Xot statedAaDiopside. Pd

Pt

Xot stated.

15% CaO... 85% SiOj

Xot stated.

(a) Au

Pd

PtRh

(b) Au

Pd.

Pt

AlaOs..

Xot stated Xot stated

1555

1201.-

1391.5

1549.5

1062.6. 1391.5

1549.5 1755

1710.

1063.. 1552

1769 1960

1063 1552

1769

2040.

Slightly oxidizing. (Int. 1927).

Xitrogen at one atm

Xitrogen at one atm...

(Int. 1927).

(Int. 1927).

Xitrogen—slightly

oxidizing.

Air.

(a) Oxygen at 1 atm..

(b) Air at 1 atm

(c) Oxygen at 0.0575.. atm.

Small oxygen pres- sure

Air.

Xot stated _

(a) and (b) Air_

Either helium, hydrogen, or vacuum.

Geophysical

(Int. 1948).

(Int. 1927).

Geophysical.

(Int. 1927).

Int. 1948.

ant. 1927).

Int. 194«.

Int. 1948.

1369.

1370.

1371±1.

2330i20.

1368.

1368.

1380±5

1591

(a) 1583±2.

(b) 1594±2

(c) 1597±2

1591±5

1650

1725±15....

1740±25.-.

(a) and (b) 179o±15.

1369±r

1382±5.

1591.

13S0±2*

1591±2* 1594±2*

1594±o*

1647.

1725±15.

1736=25.

1795±15«

2330±20.

FeO

Fe304

; temperature uniformity be- tween specimen and target area of pyrometer not verified.

Ga2 03

(«)-

; authors stated emissivity of approximately 0.9 to 0.95 is probably overestimated. Reflection errors probable.

Gd2 03

690165—63 3 15
TABLE 1

i

Reference Parity 2 Furnace type Temperature measurement Method

Curtis and Johnson

[71]. Y—0.2%; La<0.05%; Ce—

0.5%; Pr<0.l%; Nd—

0.5%; Sm—0.5%; Eu—

0.5%; Dy—0.5%; Tb—

2.0%; Ho<0.5%; Er<

0.05%; Yb<0.05%; Lu—

0.05' !

Not stated. Optical pyrometer sighted on

specimen.

Schwarz, Schenk, and Oiese [72]

Laubengayer and Morton [73].

Clausing [74]

Mark [27]...

Henning [75]

Curtis, Doney, and

Johnson [76].

Not stated.

<0.01% impurities.

ZrOj<l%-

Fe and Si—0.5-1%; Zr- 5%.

"Pure theoretical"

Zr-2 ppm; Tl-1000 ppm;

Al-600 ppm; Fe-100 ppm; Si—100 ppm.

Resistance; quench type, Pt wire-wound ceramic tube heating element.

Resistance; quench type, Pt wire-wound ceramic

tube heating element.

Resistance; bar-shaped W

strip heating element.

Resistance; graphite or metal strip heating ele- ment.

Resistance; W tube heatting element.

Flame; oxyacetylene.

Thermocouple.

Pt-PtRh thermocouple adja- cent specimen.

Optical pyrometer sighted on

small cavity adjacent to specimen cavity.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer.

Observation of rod shaped

specimen during heating. Definite fluidity of specimen

indicated melting.

Examination with microscope

of quenched specimen after heating. Disappearance of

last crystal indicated melting.

Eaxmination with microscope

of quenched specimen after heating. Disappearance of

last crystal indicated melting.

Observation of specimen during heating. Flowing speci- men indicated melting.

Observation of specimen during heating.

Observation of specimen during heating.

Not stated.

Schneider [62].

Cordfunke and Meyer [77].

Al, Ca, Cu, Fe, Mg, Ni, P, and Si, each <0.01%; Er <0.00l%; Ag and Mn <0.00001%

Not stated.

Induction; crucible-shaped

Ir susceptor.

Resistance; "Silibar".

Optical pyrometer sighted on

small hole in crucible lid.

Pt-90Ptl0Rh thermocouple .

Examination of specimen after heating. Flat button indi- cated melting.

Vapor pressure dataRuff [31]

Contained didymium impurities.

Lambertson and

Gunzel [30].

v. Wartenberg and

Reusch [56].

Chemistry and

Physics Handbook w.

100%.

Resistance; carbon tube

heating element.

Resistance; W heating

element.

(Flame) "Fletscheroven"

Not stated. Not stated.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen. Specimen not

visible.

Optical pyrometer sighted on

specimen.

Not stated.

Observation of specimen

during heating.

Examination of specimen after heating.

Observation of specimen

during heating.

Not stated.

See footnotes at end of table.
—Continued

Calibration Points

Materials Temp.

Environment Original Temp.

Scale 3

Melting Points

Original Int. 1948 *

Comments Oxide

Not stated.

Na2 SO<. K2SO4-

Li2Si03.

Not stated.

Not stated.

Not stated.

Not stated.

Not stated.

Au.

Pt-. Rb.

Not stated.

Pt.

Pt.

Pt.

Not stated.

884.7..

1069.1 1201.8

1063. 1769

1960

1755.

(1769)

(1773).

(Int. 1948)2350±50. 23S0±50_

Air

(Air).

Hydrogen.

(Geophysical) ...

(Int. 1927).

(Int. 1927).

1115±3.

1116±4.

1115±3*

1116±4*

2774±25. 2758±25.

Neutral. (Int. 1948). 2770. 2770.

Nitrogen or hydrogen. Not stated. 2812±25.

Not stated. (Int. 1948). 29U0±2.-.. 2900±25

Air. Int. 1948. 1910±10. 1910±10.

Oxygen at 1 atm. Int. 1948. 1100 dissociates. 1100.

Not stated.

Helium.

C3 =1.46 cm deg

(Int. 1948).

1840- 1859.

2210±20. 2210±20.

Air. (Int. 1927). 2315. 2307.

Not stated . Not stated. >1700_

!

; authors stated an attempt was made to correct for nonblack- body conditions.

Gd2 OtCon.

GeOj

Quartz

type.

5

; temperature uniformity be- tween specimen and target area of pyrometer not verified.

s

; reflection errors probable.

5

; melting point determind for impure Hf02 sample and

extrapolated to 100% es

HfOj

No melting point data located

in the literature.

No melting point data located in the literature. Because of the

reactivity of K2 0, it is unlikely that a melting point can be determined.

s ; reaction between specimen and Zr02 support probable.

H01O3

I113O3

IrOa

K2 Q

La2 Os

(

s)-

Survey, not original data. Because of the reactivity of Li2 0

it is unlikely that a melting

point can be determined.

Lia O

17
TABLE 11

Oxide Reference Parity 2 Furnace type Temperature measurement Method

L112O3

Ruff [31].

Kelley [1].

McNally, Peters, and Ribbe [33].

Kanolt [37].

Tiede and Birnbrauer

[23].

White, Howat and Hay [78].

v. Wartenberg and

Prophet [53].

Van Hook and Keith

[79].

Ranganathan, Mackean and Muan [80].

v. Wartenberg, Reusch and Saran

[44].

v. Wartenberg and

Gurr [52].

Carnelley [81]-

Groschufl [82].

v. Jaeger and Germs

[83].

Hoermann [84]

See footnotes at end of ta

Contained: H2CO3, H2 0,

FeiOj, Si(OH)4 and

NaCl.

Not stated.

C0304 and WO3—0.01- 0.1%; SiOj and Fe2 03—0.005- 0.05%; AI2O3 and CrjOa—0.001- 0.01%; Ba 03 , V2O3, TiOj, and CuO—5-50 ppm; MnO and AgjO—1-10 ppm.

CaO—none AI2O3—0.0002%. Fe—0.0005%. COj—0.130%. CI—0.275%. SOj—0.001%. HNO3—none.

Not stated.

Not stated

Not stated

Not stated

Reagent grade

Commercially pure

Pure

Not stated..

Not stated.. -.

Purified—

Not stated..

ble.

Resistance; carbon tube

heating element.

Not stated.

Induction; graphite tube

suseeptor.

Resistance; graphite tube

heating element.

Arc.

Resistance; Mo wire- wound ceramic tube

heating element.

Flame; oxyhydrogen or

gas-air.

Resistance; quench type, Pt wire-wound ceramic tube heating element.

Resistance; Mo wire- wound ceramic tube

heating element.

Flame; oil-oxygen—.

Not stated

Flame; "Bunsen lamp"—.

Not stated.

Resistance; nichromewire

heating element.

Resistance; Pt wire heat- ing element.

Optical pyrometer sighted on

specimen.

Not stated.

Optical pyrometer sighted on

small hollow graphite cyl- inder adjacent to specimen.

Optical pyrometer sighted on blackbody cavity immersed

in specimen.

Optical pyrometer sighted on

specimen. Mo-W thermocouple adjacent

to the specimen.

Optical pyrometer .

Pt-90PtlORh thermocouple

adjacent to specimen.

Pt-90PtlORh thermocouple

adjacent to specimen.

Optical pyrometer

Optical pyrometer

Mercury thermometer

Not stated —

Thermocouple immersed in specimen.

Pt-PtRh thermocouple im- mersed in specimen.

Observation of during heating. specimen

Not stated.

Observation of during heating. specimen

Thermal analysis; heating

curves.

Observation of specimen

during heating.

Differential thermal analysis.

Not stated .

Examination with microscope

of quenched specimen after heating.

Examination with X-rays and microscope of quenched

specimen after heating.

Observation of specimen sus- pended in furnace during

heating.

Not stated.

Not stated.

Thermal analysis; heating and

cooling curves.

Thermal analysis, heating

curves.

Observation of specimen during heating.
—Continued

Calibration Points

Materials Temp.

Environment Original Temp.

Scales

Melting Points

Original Int. 1948 *

Comments Oxide

Pt.

Not stated.

AljOs

SbCu-Ag eutectic. AgCu

Diopside.

Pt__

Not stated.

Fe trans- formation. Fe

Not stated.

CaS103 .

1755.

2044.

630... 779

960.5 1083

1391

1755

1400.

1530

1544.

CaS103 90SlOj:10CaO. Pt

1546. 1707

1769

Not stated.

Not stated.

Not stated.

Not stated.

Not stated .

Not stated.

(a) Nitrogen at 10-30 mm Hg.

(b) Nitrogen at 1 atm

(c) Nitrogen at 10-30 mm Hg.

(d) Nitrogen at 1 atm

(e) Nitrogen at 10-30 mm Hg.

Not stated.

Nitrogen.

Carbon monoxide and

nitrogen at atmospheric pressure.

Vacuum . _

Not stated.

Air

Air

Air

Air

Air

Not stated

Air

Oxidizing

Not stated

C2=1.46 cm deg. (a) 2120. 2150.

Not stated.

Int. 1948...

(b) 2250-2280

(c) 2450

(d) 2500

(e) 2550

2642

2825±20.

2285-2316

2494

2546 2599

2825±20.

t

9)- 2852*

Not stated

(Int. 1927)

(Int. 1927) __

(Geophysical) ...

Int. 1948

(Int. 1927)

(Int. 1927)

Not stated

Not stated

Not stated

(Int. 1927)

1650.

1785. 1781.

1560 1557

1562. 1564*

1567±5_ 1567±5*

1590±20. 1587±20.

1705. 1701.

759.

791.

795.

795.

No melting point data located

in the literature.

• ; various melting points obtained using different shaped

specimens and graphite supports. Reaction with graphite and partial reduction of MgO occurred.

Survey; not original data.

Temperature uniformity be- tween specimen and target area of pyrometer not verified.

L112O3

MgO

(

5)- MnO

M113O4

(

s)-

M0O3

19
TABLE 1

Reference Purity > Furnace type Temperature measurement Method

Rieck [85]. Purifled. Flame; gas-air.

Cosgrove and Snyder Trace—heavy and alkali metals.

Resistance; nichrome wire- wound ceramic tube

heating element.

Pt-PtRh thermocouple Im- mersed in specimen.

Pt-PtRh thermocouple

(Thermal analysis).

Thermal analysis, cooling curves.

Brauer [87]. Ti02—0.28%. "Tammann oven". Optical pyrometer sighted on

specimen.

Shafer and Roy [

Ibrahim, Bright, and Rowland [89].

Roth and Waring [90].

Reisman and Holtzberg [91].

Roth and Waring [92].

Holtzberg, Reisman,

Berry, and Berkenblit [93].

Diamond and Schnei- der [28].

Roth and Coughanour [94].

Orr [95].

Ta2 O6 <0.2%.

99+%.

Si <0.01%; Ca and Mg <0.001%;

As, Cu, and Ta perhaps

present.

Taa O3 <0.2%.

99.7+%.

Ta<0.2%.

Resistance; Pt wire-wound

ceramic tube heating

element.

Resistance; Pt wire-wound

tube heating element.

Resistance; quench type Pt alloy wire-wound

ceramic tube heating element.

Resistance; Pt wire-wound

ceramic tube heating

element.

Resistance; quench type, Pt alloy wire-wound

ceramic tube heating

element.

Resistance; kanthal wire heating element.

Thermocouple.

Observation of specimen during heating. Flowing speci- men indicated melting.

Not stated

99.7+%.

99. 7+%.

Solar.

Resistance; Pt alloy heat- ing element.

Pt-90PtlORh thermocouple..

Pt-90Ptl0Rh thermocouple

adjacent to the specimen.

Pt-90Ptl0Rh thermocouple immersed in specimen.

Pt-90PtlORh thermocouple

adjacent to specimen.

Pt-90Ptl0Rh thermocouple immersed in specimen.

Optical pyrometer sighted on

specimen.

Pt-90PtlORh thermocouple...

Observation of cone shaped

specimen during heating. Complete slumping indi- cated melting.

Examination of quenched

specimen after heating.

Differential thermal analysis.

Examination of quenched

specimen after heating.

Differential thermal analysis.

Observation of bar-shaped specimen during cooling.

Examination of pyramidshaped specimen after heating.

Ruff [31].

Si<0. 03%; Mg<0. 05%; Ti<0. 01%

Ta2 0i-l-2%

Not stated. Thermocouple.. Not stated.

Lambertson and Gunzel [30].

Merica and Waltenberg [96],

v. Wartenberg and

Prophet [53].

v. Wartenberg and

Gurr [52].

See footnotes at end of table.

99%.

Not stated.

Resistance; carbon tube

heating element.

Resistance; W heating

element.

Not stated.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen. Specimen not vis- ible.

Optical pyrometer...

Observation of specimen during heating.

Examination of specimen after heating.

Not stated.

99. 9%.

Pure.

Flame; oxyhydrogen or

gas-air.

Not stated

Optical pyrometer..

Optical pyrometer..

Not stated.

Not stated..

20
—Continued

Calibration Points

Materials Temp.

Environment Original Temp.

Scale a

Melting Points

Original Int. 1948 *

Comments Oxide

NaCl.

Sn, Pb, Al, Cu, Ag, Si. Steam

"C

Not stated

Not stated.

°C

Air. (Int. 1927). 795±2_ 795±2.

Nitrogen at 1 atmo. Int. 1948. 795.36- 795.36*.

Not stated .

Not stated. Oxygen.

Not Stated . Not Stated.

Au

Pd

Pseudowollastonite.

Au.

Not stated. Not stated Not stated

1063.

Air.

Air.

KaC03 . NaCl..

Au

Barium disili- cate.

Not stated Not stated

1063. 1420

Oxygen plus air.

Air.

ENb03 Transformations.

None

215. 425(Air).

Air.

Not stated- Air.

Au. (1063). Not stated.

Pt. 1755. Not stated.

Pt. (1769). Helium.

(Int. 1927).

(Int. 1948).

Int. 1948.

Int. 1948.

(Int. 1948).

Int. 1948.

(Int. 1948).

Int. 1948.

Int. 1948.

(Int. 1948)

Cj-1. 46 cm deg.

(Int. 1948).

Not stated. (a) Vacuum (b) AirNot stated. Air.

Not stated. Air.

Not stated.

(Int. 1927)..

(Int. 1927)..

1460±5.

1465±5.

1479.

1485±5.

1486±5.

1487.

1491±2.

1496.

1500 ± 10.

1512.

1520.

2272 ± 20.

1458 ±5.

1465±5.

1479.

1485±5*

1486 ±5*

1487.

1491±2*

1496.

1500 ± 10.

1512.

1530.

2272 ± 20.

(a) 1552 (b) 1660

1990. 1984.

2090.

No melting point data located in the literature. Because of the

reactivity of NaaO, it is unlikely that a melting point can be determined.

0).

M0O3—

Con.

Na20

Nb2 06

Authors stated that recorded temperatures may be as much

as 20 °C low.

' ; emissivity stated by authors

to be about unity.

» ; reaction between specimen and Mgo support probable. Nd2 Os

NiO

(«)-

s ; authors stated this melting

point to be in error. See pre- ceding reference [53] for cor- rected value.

21
TABLE 1

i

Reference Purity Furnace type Temperature measurement Method

v. Wartenberg [97] Not stated. Resistance.

Chemistry and Phys- Not stated.

ics Handbook [4]. Not stated.

Thermocouple adjacent to specimen.

Not stated .

Observation of specimen dur

tag heating. Also from in- tersection of vapor pressure

curves.

Not stated.

Kelley [1].

Hoeflake and Scheffer

[98].

Balladen [47].

Hilpert and Weiller

[99].

v. Jaeger and Oerms

[83].

Schenck and Rass- bach [100].

Geller, Creamer, and

Bunting [101].

Krakau [102].

Kroll [103]....

Cooper, Shaw, and

Loomis [104].

Not stated. Not stated. Not stated. Not stated.

Purified.. Resistance; "oven". Pt-PtRh thermocouple.

Not stated. Resistance.

Not stated. Resistance.

(a) 99.2%

(b) Not stated

(e) Not stated

Pure

0.02% total impurities.

0.1-0.27c impurities.

Not stated .

Pure.

Resistance; nichrome heat- ing element.

Resistance.

Not stated.

Not stated.

Resistance; Pt heating

element.

Resistance.

Pt-PtRh thermocouple im- mersed in specimen.

Pt-PtRh thermocouple im- mersed in specimen.

Thermocouple immersed in specimen.

Pt-PtRh thermocouple.

Pt-PtRh thermocouple.

Observation of specimen during heating. Also from

vapor pressure data.

Thermal analysis, cooling

curves.

Thermal analysis.

Thermal analysis..

Pt-PtRh thermocouple.

Thermocouple immersed in specimen.

Pt-PtRh thermocouple.

Thermal analysis, cooling curves.

Differential thermal analysis.

Thermal analysis, cooling

curves.

Thermal analysis, cooling curves; also observation of specimen.

(Thermal analysis.)

PmOii

Chemistry and Physios Handbook [4]. Not stated. Not stated. Not stated. Not stated.

KeUey [1]. Not stated. Not stated. Not stated. Not stated.

See footnotes at end of table.

22
—Continued

Calibration Points

Materials

Not stated.

Not stated.

Temp.

Not stated.

Naphthaline

Benzo- phenone. Sulphur Sb

Not stated.

Not stated.

Not stated.

Not stated.

K2SO4 Transformation. KCl( K2 SO(

Not stated.

Not stated..

Not statedNot stated.

Not stated.

218. 306

444.5 630

583±1...

770.3 1069.1

Environment

About 11 mm Hg.

Not stated _

Not stated.

4600 mm Hg.

Not stated.

Air.

Oxidizing.

Air.

Air.

(Air).

Not stated.

Not stated.

Original Temp.

Scale 3

Not stated.

Not stated.

Not stated.

Not stated.

Not stated.

Not stated.

Not stated .

Not stated.

Int. 1927

(Int. 1927).

Not stated.

Not stated.

Melting Points

Original

40.1

569 Triple point.

870.

Not stated.

Not stated.

870.

(a) 877.

(b) 879

(c) 879

879.

886.

450-

296.

Int. 1948 *

569_

Comments

Ciystal form not indicated. The

reported melting point is prob- ably determined from mixture of both the white and yel- low types.

Survey, not original data

Survey, not original data..

No melting point data located

in the literature. The oxide probably dissociates to the metal before melting.

No melting point data located

in the literature.

Survey; not original data. The

oxide probably dissociates to the metal before melting.

No melting point data located

in the literature.

Survey, not original data

Oxide

Os04 yellow

type

P2 Os .

PbO

yellow

type.

No melting point data located

in the literature. The oxide probably dissociates to the metal before melting.

Pd02

PreOi,

pto2

Rb2 0

Re2 07

Rh2 03

23
TABLE 1

Reference Purity i Furnace type Temperature measurement Method

Hincke [105].

Schneider and Waring [70].

Chemistry and Physics Handbook [4],

Wietzel [106]

Endell and Rieke

[107]

White, Howat, and Hay [78]

Ferguson and Merwin [108]

Greig [109].

Zhirnova [110]-

Ruff and Lauschke

[25]

Wisnyi and

Pijanowski [61]

Curtis and Johnson

[71]

Ruff [31].

Not stated.

99.9%.

Not stated.

Not stated.

99.9%.

Not stated

Not stated .

Very pure.

Not stated.

Not stated .

Not stated.

Y<0.05%; La<0.05%;

Pr<0.2%; Nd<0.05%;

Ho<0.02%; Er<0.05%; Eu-O.4%; Gd—0.03%; Tb<0.01%; Dy—0.02%; Yb<0.05%.

Not stated.

Barczak and Insley ma.

See footnotes at end of table.

Not stated.

Not stated.

Induction; crucible shaped Ir suseeptor.

Not stated.

Resistance; Ir heating ele- ment.

Resistance; Ir heating ele- ment.

Resistance; Mo wire- wound ceramic tube

heating element.

Resistance; quench type, Pt alloy wire-wound

ceramic tube heating element.

Resistance; quench type, Pt alloy wire-wound

ceramic tube heating

element.

Flame; acetylene-Oj

Resistance; graphite tube

heating element.

Resistance; V-shaped W

strip heating element.

Not stated.

Resistance, carbon tube

heating element.

Not stated .

Not stated.

Optical pyrometer sighted on

small hole in crucible lid.

Not stated.

Optical pyrometer sighted on Pt blacked with FeaO.

Ir-IrRh thermocouple adja- cent to specimen.

Mo-W thermocouple.

Pt-90PtlORh thermocouple. Temperature measured before and after each determination.

Pt-90PtlORh thermocouple

adjacent to the specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Not stated..

Calculated from vapor pres- sure data.

Examination of specimen after heating.

Not stated.

Examination of specimen after heating. First glass formation indicated melting.

Examination of specimen after heating.

Observation of specimen

during heating.

Examination with microscope

of quenched specimen after heating. Last trace of crystals indicated melting.

Examination with microscope

of quenched specimen after heating. Last trace of crystals indicated melting.

Observation of cone shaped

specimen during heating. Slumping of the cone indi- cated melting.

Observation of specimen

during heating.

Observation of specimen

during heating. Apparent

disappearance of specimen

indicated melting.

Observation of rod shaped specimen during heating. Definite fluidity of speci- men indicated melting.

Observation of specimen during heating.

Differentia] thermal analysis. Also examination of speci- men after heating.

24
—Continued

Calibration Points

Materials Temp.

Environment Original Temp.

Scale 3

Melting Points

Original Int. 1948 *

Comments Oxide

Not stated.

An...

Pd... Pt—

Eh...

Not stated.

Pd.

An.

Pd.

Pt..

Fe trans- formation. Fe

Pd.

Ice. Au.

Pd.

Pt..

Pt-.- AbOj.

CaO..

An...

CaFi.

AUOj.

Not given.

Pt.

Not stated.

1063. 1552

1769

1960

1556.

1063. 1549

1755

1400—

1530

1549.5.

0...

1062.6

1549.5 1755

1755. 2050

2570

1062.4. 1398

2040.

1755.

8.5 mm Hg.

Air.

Not stated.

Air.

Nitrogen.

Not stated.

Air.

Air.

Air.

17.0 mm Hg.

Either helium, hydrogen, or vacuum

Air.

Not stated .

Not stated.

(Int. 1927). 655_

Int. 1948. <2405.

Not stated. 240-250-

(C2 =1.437 cm

deg).

(Geophysical)...

(Int. 1927).

1696±10.

1685.

1705.

Geophysical. 1710±10_

Geophysical. 1713±5.

(C2 =1.457 cm

deg).

(C2 =1.437 cm

deg.)

Int. 1948.

1715±20.

1850.

2300±50.

(Int. 1948). 2350±50.

C2 =1.46 cm deg.

(Int. 1948).

(a) 1385.. (b) 1625.

1630±5.

655.

<2405.

1691±10.

1692.

1701.

1720±10.

1723±5«

1728±20.

1850.

2300±50.

2350±50.

1391. 1637

1630±5.

No melting point data located

in the literature.

Survey, not original data. The

oxide is extremely volatile.

RuO<

Sb2 OS

ortho- rhombic type

Sc2 03

Se02

SiOs cristo- balite type

(

s).

t; reaction between specimen and graphite support probable.

' ; authors' stated emissivity of approximately 0.9 to 0.95 is probably overestimated. Reflection errors probable.

!

; authors' stated an attempt was made to correct for non- blackbody conditions.

5 reaction between specimen and

(a) MgO or (b) ZrOj supports

probable.

Possible reaction of SnOj with Pt container probable.

SmjOa

SnOj

25
TABLE 1

Reference Purity > Furnace type Temperature measurement Method

Schumacher [43]. C. P. grade.

Heisman, Holtzberg,

Berkenblit, and

Berry [112].

Ruff [31]

TiOj<0.001%-

Nb2 05—7.1%.

Resistance; boat-shaped W strip heating element

Resistance, U-shaped Rh

or Pt alloy strip heating element.

Resistance; carbon tube

heating element.

Optical pyrometer sighted on W strip adjacent to speci- men; spectral emissivity equals 0.431.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Observation of specimen dur- ing heating.

Observation of specimen dur- ing heating.

Observation of specimen dur- ing heating.

Kracek [3]. Not stated. Not stated

Not stated

Not stated.

Tiede and Birnbrauer

[23].

Ruff [31]

Commercially pure- Arc .

Pure- Resistance; carbon tube

heating element.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Observation of specimen dur- ing heating.

Observation of specimen during heatiing.

Trombe [2].

Ruff, Ebert, and

Woitinek [113].

Lambertson and

Gunzel [30].

Statton [114].

Not stated.

"Pure"

Not stated

Flame; oxyacetylene.

Not stated -

Optical pyrometer.

Not stated.

Not stated .

99.7%.

Reagent grade.

v. Wartenberg and

Prophet [53].

Sigurdson and Cole

[115].

Rase and Roy [116].

Not stated.

Not stated.

Not stated.

Coughanour and De Prosse [117].

St. Pierre [118].

99.9%.

Diamond and Schnei- der [28].

See footnotes at end of table.

Si—0.04%; Mg—0.02%; Ca—0.01%.

About 99.9%

Resistance; W heating

element.

Resistance; Mo strip heat- ing element.

Flame; oxyhydrogen or

gas-air.

Resistance; Pt strip heat- ing element.

Resistance; U-shaped Pt

alloy heating element.

Resistance; ThOa heating element.

Induction; carbon tube

susceptor.

Optical pyrometer sighted on

specimen. Specimen not

visible.

Optical pyrometer sighted on Mo strip adjacent to speci- men. Corrected for spectral emissivity of Mo.

Optical pyrometerExamination of specimen after heating.

Observation of specimen during heating.

Not stated.

Solar.

Optical pyrometer sighted on

Pt strip adjacent to speci- men. Corrected for spectral emissivity of Pt.

Optical pyrometer sighted on

Pt alloy strip.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Observation of specimen during heating.

Observation of specimen during heating.

Observation of pyramidshaped specimen during

heating.

Observation of specimen during heating.

Observation of bar-shaped specimen during cooling.

26
—Continued

Calibration Points

Materials Temp.

Environment Orieinal Temp.

Scale 3

Melting Points

Original Int. 1948 <

Comments Oxide

Not stated.

Diopside 15% CaO: 85% Si02 ..

Pt

Not stated

Not stated.

Pt.

Not stated.

Not stated.

Pt.

Pd.

Pt..

Not stated.

Au

Na2 Ti3 07.-- BaFj

CaMgSi2 0«. MgTi2 03 ...

Diopside Pseudowollastonite. 15% CaO: 85% SiOj.

Pt

Not stated.

None.

1392.

1712

1755.

1755.

(1769)

1555. 1774

1063... 1128

1280 1391

1660

1391.5.

1.544

1698

1769.

Hydrogen at 0.2 atm.

(Air).

C2 =1.433 cm

deg.

Int. 1948.

2430.

1872±10-

Nitrogen at reduced

pressure. C2 =1.46 cm deg 1875.

Not stated

Vacuum _

Nitrogen at reduced

pressure.

Not stated.

Not stated

Helium

Vacuum

Air.

Oxidizing.

(Air).

Air.

Air.

Air.

Not stated.

Not stated .

C2 =1.46 cm deg.

Not stated .

(Int. 1927)..

(Int. 1948)

(Int. 1927).

(Int. 1927).

(Int. 1948).

( Geophysical) ~

Int. 1948.

Int. 1948.

732. 6.

2000.

2425.

2440. 2470.

3000

3050±50.

3220±50.

1720.

1825.

1825.

1S30-

1839±10_

(Int. 1948) - 1840±10

1840.

2420.

1872±10.

1895.

2468. 2483

2515

3030±50.

3220±50*

1716.

1820.

1825.

1839±10.

1840.

5

; temperature uniformity be- tween specimen and target area of pyrometer not verified; reflection errors probable. 0

5 ; reaction between specimen and Zr02 support probable. No melting point data located

in the literature.

Survey; not original data. This

oxide is very volatile and has

a tendency to sublime rather than to melt.

(')-

»; reaction between specimen and ceramic supports probable.

Survey, not original dataMelting point extrapolated from

liquidus curves of the ZrOr- Th02 system.

5

; temperature uniformity be- tween specimen and target area of pyrometer not verified. Reduction of Ti02 very probable.

s

; partial reduction of Ti02 prob- ably occurred.

W-

(«)-

09-

1840±10 (5)

5 ; emissivity stated by authors

to be about unity.

SrO

Ta2 05 alpha

type.

Tbi07

TeQ2

ThOj

TiOj

27
TABLE 1 l

Reference Purity I Furnace type Temperature measurement Method

v. Wartcnbcrg and

Gurr [52].

Lang, Fillmore, and

Maxwell [119].

v. Wartenberg and

Eckhardt [57].

Brauer and Littke

[120].

Not stated.

'.r.i.'.v

Pure; SiOj free.

>99.8%.

Duncan [121]. Not stated.

Not stated. Optical pyrometer. Not stated.

Resistance; ThOj heating

elements.

Flame; acetylene-Oj.

Solar.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Radiation pyrometer sighted on specimen.

Observation of pyramidshaped specimen during

heating.

Observation of specimen sus- pended in furnace during

heating.

Observation of specimen during heating.

Not stated. Pt-90PtlORh thermocouple immersed in specimen. Thermal analysis, cooling curves.

Ruff and Goecke [34]..

Wisnyi and Pijanowski [61].

Ehlert and Margrave

[122].

Lambertson and

Gunzel [30].

Kracek [3]

Carnelley [81].

Cook [123]

Not stated.

Not stated.

Not statedVery pure.

Not stated.

Not stated.

Purified

Jllarionov, Ozeron, and Kil'disheva

[124].

Holtzberg, Reisman,

Berry, and Berkenblit [125].

McDaniel [126]

Not stated.

99.94%.

99.5%.

Burdese [127]. Not statedChemistry and

Physics Handbook

[4].

v. Jaeger and Germs

[83]. See footnotes at end of table,

Not stated.

Fe-0.05%.

Resistance; graphite tube

heating element.

Resistance; V-shaped W

strip heating element.

Induction; graphite sus- ceptor.

Resistance; W heating

element.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen. Correction made

for spectral emissivity.

Optical pyrometer sighted on

specimen. Specimen not

visible.

Observation of cone-shaped specimen during heating.

Observation of specimen during heating. Apparent dis appearance of specimen in- dicated melting.

Observation of specimen during heating.

Examination of specimen during heating.

Not stated

Flame; "bunsen lamp"....

Not stated

Not stated

Mercury thermometerThermocouple

Not stated.. _.

Not stated

Heat content curves.

Not stated. Pt-PtRh thermocouple.

Not stated.

Resistance; Pt alloy wire- wound ceramic tube

heating element.

Not stated..

Pt-90PtlORh thermocouple immersed in specimen.

Pt-90PtlORh thermocouple immersed in specimen.

Differential thermal analysisThermal analysis.

Not stated .

Not stated _ Not stated _

Thermal analysis; electrical conductance versus temperature curves.

Examination with microscope

of specimen after heating.

Not stated

Resistance; nichrome wire Thermocouple immersed in heating element. specimen. Thermal analysis, heating

curves.
—Continued

Calibration Points

Materials

Not stated.

Not stated.

Not stated.

CaF2.. NiO„

Cr203 . AI2O3-

Not stated.

Au.

Pt..

AljO,.

Not stated.

Pt.

Not stated.

Not stated.

Au...

Pd...

Not stated.

NaCL. KaS04 .

NaCl.

Not stated.

Not stated.

Not stated.

Temp.

Not stated. Not stated Not stated Not stated

1071. 1757

2040.

(1769).

(1063).

(1555)

800.4. 1069

800-

Environment

Air.

Air.

(a) Oxygen at 300 torr. Argon at 460 torr. (b) Oxygen at 500 torr. Argon at 260 torr.

(c) Oxygen at 600 torr. Argon at 160 torr. (d) Oxygen at 760 torr.

(e) Oxygen at 1140

torr.

Oxygen at 1 atm

Nitrogen.

Either helium, hydrogen, or vacuum.

Vacuum.

Helium.

Not stated.

Not stated.

Not stated.

Not statedAir + Oxygen.

Air

Carbon dioxide.

Not stated.

OxidizingOriginal Temp.

Scale 3

(Int. 1927).

Int. 1948.

(Int. 1927).

(Int. 1948).

(Int. 1927).

(C2 =1.48cm

deg).

Int. 1948.

(int. 1948)..

(Int. 1948)..

Not stated.

Not stated.

(Int. 1927)..

(Int. 1948).

Int. 1948.

Int. 1948.

(Int. 1948).

Not stated.

Not statedMelting Points

Original

1850.

1845.

1855.

(a) 1840±15_

(b) 1860±15.

(c) 1870±15.

(d) 1870±15.

(e) 1870±15.

717±5.

2176.

2760±30.

2860±45.

2878±22.

656.

658.

670-

672_

674±5.

675±3.

685±5.

1473±1-

Int. 1948 »

°C

1845.

1845.

1850.

1840±15.

1860=1=15.

1870±15.

1870±15-

1870±15_

717±5_

2208.

2760±30_

2860±45_

2878=1=22*

670-

672.

674±5*

G75±3*

685±5.

Comments

(«)-

(«)-

(0-

No melting point data located

in the literature.

• ; reaction between specimen and uranium carbide support

probable.

5

; author's stated emissivity of

0.9 to 0.95 probably overesti- mated. Reflection errors probable.

Survey; not original data.

Survey, not original data.

Oxide

TiOa—

Con.

TI2O3

Tm2 03

UO2

VjOt

WO3

29
TABLE 1»

Reference Purity 2 Furnace type Temperature measurement Method

Hoennan [84]. Not stated

Rull and Lausche [25].

RulT [31]

Commercially pureTraces of impurities.

Resistance; Pt wire heating element.

Resistance; graphite tube

heating element.

Resistance; carbon tube

heating element.

Pt-PtRh thermocouple im- mersed in specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Observation of specimen during heating.

Observation of specimen during heating.

Observation of specimen during heating.

Bunting [128].

Tiede and Birnbrauer

[23].

Ruff and Lauschke

[25].

Ruff [31] -

Clausing [74].

Podszus [129].

Henning [75]

Mark [27].

Trombe [2].

Lambertson and

Gunzel [30].

Zhirnova [110].

Curtis, Doney, and

Johnson [76].

>99.9%_

Very pure.

SiOr-0.95%-. FeaOa—0.27%

93%.

Hf02 <l%-

Pure.

Pure.

Not stated.

Not stated.

Hf02—2.03%... Others—0.03%

Not stated.

Hf—80 ppm_. Ti—60 ppm

Al—150 ppm

Fe—600 ppm

Si—200 ppm

Induction, button-shaped

Ir-Pt susceptor.

Arc.

Resistance; graphite tube

heating element.

Resistance; graphite tube

heating element.

Resistance; bar-shaped W

strip heating element.

Arc, carbon electrodes.

Resistance; W tube heat- ing element.

Resistance; graphite or metal heating element.

Not stated.

Resistance, W heating ele- ment.

Flame; acetylenesFlame; oxyacetyiene.

Optical pyrometer sighted on

small cavity adjacent to specimen cavity.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

small cavity adjacent to the specimen cavity.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Optical pyrometer sighted on

specimen.

Not stated.

Optical pyrometer sighted on

specimen. Specimen not

visible.

Optical pyrometer sighted on

specimen.

Optical pyrometerExamination of specimen after heating.

Observation of specimen

during heating.

Observation of specimen

during heating.

Observation of during heating. specimen

Observation of specimen

during heating. Flowing

specimen indicated melting.

Observation of specimen

during heating.

Observation of specimen

during heating.

Observation of specimen

during heating.

Not stated

Examination of specimen

after heating.

Observation of cone shaped specimen during heating. Slumping of the cone indi- cated melting.

Not stated.

1 All phrases, numbers, words, etc., enclosed in parentheses indicate that these items are not directly expressed in the quoted reference. However, based on information contained in the published report, the enclosed items can be reasonably assumed to be valid.

2 Purities are listed as quoted in the reference. No attempt has been made to convert them to a common basis.

3 Int. 1927—The International Temperature Scale (of 1927) [19]. Int. 1948—The International Practical Temperature Scale of 1948 [10]. Geophysical—Geophysical Temperature Scale [18]. C2—second radiation constant. This constant is required in the definition of the temperature scale. See text for more complete description of appropriate equations.

30
—Continued

Calibration Points

Materials Temp.

Environment Original Temp.

Scale s

Melting Points

Original Int. 1948 *

Comments Oxide

Not stated _

An... CaF2 -

Pt.

Not stated.

Not stated.

Au_-

CaFj

Pt.

Not stated.

Ft.

Not stated.

Not stated.

Not stated.

Pt

Pt.—

A12 03 . CaO..

Not stated.

°C

Not stated _

1062.4, 1398

1755.

Air at 21.5 mm Hg

Nitrogen at 15 mm Hg.

(Int. 1927)

C2 =1.437 cm

deg.

C2 =1.46 cm deg.

1473. 1471.

2410. 2410.

2415. 2458.

(Int. 1927). 1975±25. 1969±25_

VacuumNot stated. 2430.

1062.4. 1398

1755.

(a) Hydrogen at 760 mm Hg.

(b) Air at 8.22 mmHg.

Nitrogen

C2 = 1.437 cm

deg.

Hydrogen.

C2 =1.46 cm

deg.

(Int. 1927).-

(a) 2519

(b) 2563±10.

2585

2519

2563±10

2636

2677±25. 2663±5.

Not stated Air.

Hydrogen and nitro- gen.

Neutral

(1769).

Not stated.

Helium

Not stated.

Not stated.

(Int. 1948)

Not stated.

(Int. 1948).

(a) 2677.

(b) 2727

2687

2690. 2690-

2700

2710±15_ 2710±15.

1755. 2050 2570

Not stated.

(C2 =1.457 cm

deg.).

(Int. 1948)

2715. 2765.

2850±25. 2850±25.

s

; reaction between specimen and graphite support probable.

5

; reaction between specimen and Zr0 2 support probable.

No melting point data located

in literature.

Temperature uniformity be- tween specimen cavity and

target area of pyrometer not

verified. «

WO]-

Con.

Y2 03 .

Yb203

ZnO

Zr02

5

; reaction between specimen and graphite support probable.

Survey; not original data..

(»)-

* (A) The melting points marked with an asterisk are considered to be the better values of those listed. The values so designated do not necessarily repre- sent the true melting points, but merely highlight those values believed to be more reliable. (B) See text for method of conversion to values based on International Practical Temperature Scale of 1948. No entry in this column indicates insuffi- cient data in original paper to permit conversion of melting point to 1948 basis.

5 A close enough approach to blackbody conditions to facilitate accurate temperature measurement probably has not been obtained. As a general guideline, it should be noted that if an object in an enclosure is distinguishable from its surroundings, blackbody conditions probably have not been realized.

6 Kanolt did not specifically employ Wien's equation in the measurement of high temperatures. A complete discussion of the method of conversion to temperatures on the 1948 scale is given elsewhere [130].

U.S. GOVERNMENT PRINTING 0FFICE:I963

31



U.S. DEPARTMENT OF COMMERCE

Luther H. Hodges, Secretary

NATIONAL BUREAU OF STANDARDS

A. V. Astin, Director

THE NATIONAL BUREAU OF STANDARDS

The scope of activities of the National Bureau of Standards at its major laboratories in Washington, D.C., and

Boulder, Colorado, is suggested in the following listing of the divisions and sections engaged in technical work.

In general, each section carries out specialized research, development, and engineering in the field indicated by

its title. A brief description of the activities, and of the resultant publications, appears on the inside of the

front cover. WASHINGTON, D.C.

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Dielectrics. High Voltage. Absolute Electrical Measurements.

Metrology. Photometry and Colorimetry. Refractometry. Photographic Research. Length. Engineering

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Heat. Temperature Physics. Heat Measurements. Cryogenic Physics. Equation of State. Statistical Physics.

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Operations Research. Data Processing Systems. Components and Techniques. Computer Technology. Measurements Automation.

Engineering Applications. Systems Analysis.

Atomic Physics. Spectroscopy. Infrared Spectroscopy. Far Ultraviolet Physics. Solid State Physics. Elec- tron Physics. Atomic Physics. Plasma Spectroscopy.

Instrumentation. Engineering Electronics. Electron Devices. Electronic Instrumentation. Mechanical In- struments. Basic Instrumentation.

Physical Chemistry. Thermochemistry. Surface Chemistry. Organic Chemistry. Molecular Spectroscopy.

Elementary Processes. Mass Spectrometry. Photochemistry and Radiation Chemistry.

Office of Weights and Measures. BOULDER, COLO.

CRYOGENIC ENGINEERING LABORATORY

Cryogenic Processes. Cryogenic Properties of Solids. Cryogenic Technical Services. Properties of Cryogenic

Fluids. CENTRAL RADIO PROPAGATION LABORATORY

Ionosphere Research and Propagation. Low Frequency and Very Low Frequency Research. Ionosphere Research. Prediction Services. Sun-Earth Relationships. Field Engineering. Radio Warning Services. Vertical Soundings Research. Troposphere and Space Telecommunications. Data Reduction Instrumentation. Radio Noise. Tropospheric Measurements. Tropospheric Analysis. Spectrum Utilization Research. Radio-Meteorology. Lower Atmosphere Physics.

Radio Systems. Applied Electromagnetic Theory. High Frequency and Very High Frequency Research. Fre- quency Utilization. Modulation Research. Antenna Research. Radiodetermination.

Upper Atmosphere and Space Physics. Upper Atmosphere and Plasma Physics. High Latitude Ionosphere

Physics. Ionosphere and Exosphere Scatter. Airglow and Aurora. Ionospheric Radio Astronomy.

RADIO STANDARDS LABORATORY

Radio Standards Physics. Frequency and Time Disseminations. Radio and Microwave Materials. Atomic

Frequency and Time-Interval Standards. Radio Plasma. Microwave Physics.

Radio Standards Engineering. High Frequency Electrical Standards. High Frequency Calibration Services. High Frequency Impedance Standards. Microwave Calibration Services. Microwave Circuit Standards. Low

Frequency Calibration Services. Joint Institute for Laboratory Astrophysics-NBS Group (Univ. of Colo.).