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Heatpipe Furnace Models 17702W, 17702P, 17702S (13
–
07/20)
INTRODUCTION
•
Essentially Gradient Free
•
Heat pipe Operation from Indium to Copper
•
Simple Use - no zone offsets to adjust
Isotech metrology furnaces have more than 35 years of proven
use and are widely used by the worlds’
leading NMIs. For the optimal use of fixed point cells, the temperature uniformity should be less than 10mK
over the length of the fixed point sample CCT/2000-
13, “Optimal Realization of the Defining Points of the
ITS-
90...”
Isotech heat pipe furnaces offer essentially gradient free operation; heat pipes provide the ideal conditions
for the creation and maintenance of ITS-90 fixed point cells. Unlike some other companies Isotech can
provide heat pipe furnaces to suit Indium, Tin, Zinc, Aluminium, Silver and Copper fixed points.
Plateau length is determined by the difference in temperature between the heat pipe and cell - this can be
adjusted to give a plateau of any length of up to tens of hours. Our controllers offer extra resolution and
allow adjustment to 0.1°C right up to 1100°C. The Potassium and Sodium models have a cooling coil in the
lid with connections to circulate tap water to keep the furnace lid cool protecting the SPRT and reducing
heat load into the lab. A pre-warming tube with a temperature approximately equal to that of the heat pipe
made of a unique, gas-tight material is provided to heat the SPRT prior to it being placed in a cell. The
furnaces feature an adjustable, independent over temperature device to protect expensive cells and SPRTs
as well as a second internal over temperature safety device.
