Isotech M17705 - Defining Fixed Points and Related Data

Page 33 of 40
Dual Furnace Models M17705, N17706 & 17707 Iss.09 – 12/14
DEFINING FIXED POINTS AND RELATED DATA
FIXED
POINT
ITS 90 TEMPERATURE
PRESSURE COEFFICIENT
ITL CELL
DESIGNATION
SUITABLE
APPARATUS
FOR CELL
OPERATION
°C
K
mK/
bar
mK/m HEAD OF
SUBSTANCE
ARGON
TP
-189.3442
83.8058
(NOT
AVAILABLE
FROM ITL)
MERCURY
TP
-38.8344
234.3156
+5.4
+7.1
ITL-M-17724
ITL-M-17725
WATER
TP
0.01
273.16
-7.5
-0.73
A11/50 or B11/50
ITL-M-18233
GALLIUM
MP
29.7646
302.9146
-2.0
-1.2
ITL-M-17401
ITL-M-17402A
INDIUM
FP
156.5985
429.7485
+4.9
+3.3
ITL-M-17668
ITL-M-
17701/3/4/7
TIN
FP
231.928
505.078
+3.3
+2.2
ITL-M-17669
ITL-M-
17701/3/4/7
ZINC
FP
419.527
692.677
+4.3
+2.7
ITL-M-17671
ITL-M-
17701/2*/3/6
ALUMINIUM
FP
660.323
933.473
+7.0
+1.6
ITL-M-17672
ITL-M-
17702**/5/6
SILVER
FP
961.78
1234.93
+6.0
+5.4
ITL-M-17673
ITL-M-
17702**/5/6
NOTES:
1. TP = Triple Point, MP = Melting Point, FP = Freezing Point
2. Pressure corrections that apply to triple point and to other sealed-cell measurements are determined solely
by the pressure head of material in the cell; variability of atmospheric pressure has no effect on the
measurements.
* Furnace with potassium heat-pipe for zinc freezing point.
** Furnace with either potassium or sodium heat-pipe at aluminium and silver freezing points.