Fluke 9112A - Manual (Page 21)

5.2 Heater Assembly
The heater is a made of fiber ceramic insulating material with imbedded heat-
ing. The heater is made up with two halves, each with a separate heating ele-
ment. The heating elements are wired in parallel.
The heater is primarily a radiating device and is rated for a maximum furnace
operating temperature of 1100°C. Realize, however, that the higher the operat-
ing temperature, the lower the lifetime of the heater. Limiting the number of
hours at the extreme high end of the temperature range to only the time re-
quired for calibrations increases the longevity of your furnace heating element.
5.2.1 Equilibration Block Assembly
The Equilibration Block Assembly consists of 1) the test well, 2) access tubes
and end plate, 3) the front and rear guard blocks, 4) insulation on each end and
5) the center block. The center block is intended to stabilize the temperature
fluctuations and to conduct heat between the test wells in order to equalize
them. The guard blocks shunt heat to the various probes to reduce heat loss out
the ends. The whole assembly is supported by a fused silica tube. All heated
materials are fused silica, ceramic fiber, or Inconel (alloy 600).
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5 Parts and Controls
Heater Assembly
Cutout Probe
Back
Isothermal Block Quartz Tube
Front
Guide Tubes
Control Probe
Figure 2 Sectional Side View