Quantum Design CM-C, User Manual

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Section 5.2 Chapter 5
VSM Oven Hardware Components VSM Oven Hardware
5-2
VSM Oven Option User’s Manual, Rev. A3 Quantum Design
May 2011
The VSM Oven heater stick and its parts are illustrated in Figure 5-1. It can be seen that the
heater stick is a combination device that contains the heater, thermometer, and sample holder for
the oven option. You will mount samples directly on the heater stick, using the alumina cement
included in the VSM Oven Option User’s Kit (Figure 5-5).
The heater stick is a long thin sheet of ceramic that has been silk-screened with a platinum
meander pattern and then coated with a thin layer of dielectric. The ceramic has extremely low
thermal conductivity, which allows the sample mounting areas to reach extreme temperatures
while the electrical connections remain close to room temperature. The platinum conductor acts
as the heating element of the VSM Oven option. Samples are mounted directly on top of the
platinum resistor in the indicated sample mounting area.
The back of the heater stick has the temperature-detection system of the VSM Oven option. Inlaid
in two grooves in the heater stick is a type S (platinum vs. platinum–10%rhodium) thermocouple.
The thermocouple junction is located directly opposite the sample and platinum heater. This
thermocouple provides a very precise measure of the sample temperature and it is rated for
temperatures over 1000 K.
A thermistor is embedded at the top of the heater stick, inside the protective shield. The function
of this thermistor is to correct the cold junction temperature of the thermocouple, because the
thermocouple table is referenced to a cold junction at 0 ºC.
At the top of the heater stick is the five-pin male electrical connector (Figure 5-7) that provides
power for the platinum heater and has voltage leads for the thermocouple and the thermistor. The
heater-stick connector plugs directly into the base of the VSM Oven sample rod shown in Figure
5-2.
5.2.2 Oven Sample Rod
The VSM Oven sample rod is specifically
designed for the VSM Oven option—it is not
compatible with the standard VSM option. The
primary changes were introduced to
accommodate and protect the necessary electrical
connections to the oven heater stick.
Figure 5-2 shows the oven sample rod in the
vertical position (with the magnetic lock and
strain relief at the top of the rod). Beginning at the
top of the figure, the oven sample rod consists of
the following components:
○ Electrical Connections (Top)
The top electrical connector plugs into the
feedthrough on the inside of the wired access
port. It has a five-pin male connector identical to
the heater connector (Figure 5-7) and an anodized
aluminum rim that helps you safely grip the
connector when you plug it in and remove it.
Important:
Always handle the oven sample rod
and its connectors by using the anodized
aluminum rim of the electrical connector or the
strain relief portion of the oven sample rod. Never
pull on the cable while unplugging it, as you
might loosen the electrical connections.
Figure 5-2. Oven sample rod