TA Instruments AR 2000, Руководство оператора

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AR 2000 Operator's Manual
2 8
Smart Swap™
The AR2000 features "Smart Swap" technology that automatically senses the temperature control system present
and configures the rheometer operating software accordingly, loading all relevant calibration data. The use of
this feature is covered later in Chapter 5.
The Peltier Plate
Temperature control in the standard configuration is via a Peltier
system (both a plate and concentric cylinder system are available),
which uses the Peltier effect to rapidly and accurately control heating
and cooling. The Peltier system uses a thermoelectric effect. This
functions as a heat pump system with no moving parts, and is ideally
suited to rheological measurements. By controlling the magnitude and
direction of electric current, the Peltier system can provide any desired
level of active heating or cooling directly in the plate.
A schematic of the Peltier plate is shown in Figure 3.2.
Since the Peltier system operates as a heat pump, it is necessary to
have a heat sink available. The heat sink removes unwanted waste
heat from the plate. This heat sink is normally in the form of a reser-
voir, containing a few liters of water, plus a small pump that can
provide sufficient flow rate through the Peltier heat exchanger jacket
built into the plate.
The reservoir fluid will become warm with the prolonged use of the
Peltier at high or sub-ambient temperatures.
If your temperature range is 20°C below and 60°C above ambient, the
water bath should be at room temperature. If, however, you wish to
work at lower or higher temperatures, the water bath temperature
needs to be altered accordingly (
i.e ., the Peltier system will work most
efficiently at a temperature range that is 15°C above and below the water bath temperature.). When routinely
using the Peltier system at temperatures above 100°C, it is recommended that you connect the system to a main
water supply.
The flow rate through the Peltier does not need to be high. A flow rate of at least 0.5 litre min -1 is adequate.
When working at the Peltier's lowest temperature range, increasing the flow rate to >1 liter min -1 will give a
better performance. If this flow rate is not maintained, the temperature control system will lose control and the
system will only heat.
Peltier Temperature Range
tank & pump -5°C to 100°C
pumped water supply (20°C) -20°C to 200°C
water at 60°C 10°C to 200°C
water at 40°C 0°C to 200°C
water at 1°C -30°C to 180°C
fluid at -20°C -40°C to 160°C
Figure 3.2
The Peltier Plate