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Operating Modes
The controller has two basic modes of operation:
•
Automatic mode in which the output is automatically adjusted to maintain the temperature or process value
at the setpoint. This is the normal operation mode.
•
Manual mode in which you can adjust the output independently of the setpoint.
You toggle between the modes by pressing the AUTO/MAN button.
Two other modes are also available:
•
Remote Setpoint mode, in which the setpoint is generated from an external source. In this mode, the REM
light will be on.
•
Programmer mode, further information on which can be found in the 2408 user manual.
CALIBRATION OF THERMAL SENSORS
When using the FSB-200-P-AC to calibrate thermal sensors such as thermocouples and platinum resistance
thermometers, it is important to ensure that the working volume of the bath is thermally stable. Use an
independent temperature sensor, such as a reference thermocouple, to check the temperature uniformity and
stability. See section TECHNICAL SPECIFICATION.
The temperature stability of the fluidized bath at any operating temperature may be improved by tuning the
control parameters of the temperature controller to match the performance of the system under any set
conditions. Adjustment details are contained within the manufacturers instruction manual for the Eurotherm
2408 temperature controller.
For precise calibration, the actual temperature of the fluidized bath should be measured with an independent
calibrated reference sensor; the temperature indicated by the temperature controller should only be used as a
guide and not as an indication of absolute temperature.
The number of sensors calibrated in the fluidized bath at any one time should be kept to a minimum so as not to
disturb the flow pattern within the bath. Typically, up to 10 sensors of approximately Ø10mm may be calibrated
without loss of performance.
The probe plate supplied with the FSB-200-P-AC may be machined to allow the sensors being calibrated access
to the bath. This probe plate should always be positioned above the surface of the bath in the probe plate carrier
to inhibit the loss of fine alumina particles from the surface of the bath. See Figure 5. Accessory probe holders
with integral dust extraction systems are also available. Probe holders locate the sensors being calibrated at a
known position within the bath and act as equalising blocks so that the basic isothermal properties of the
fluidized bath are further enhanced. See section ACCESSORIES.
Figure 5: Probe plate with probe plate carrier
Antylia Scientific can also offer a work basket (F7759) which ensures that probes or other items being processed
are held within the working volume of the bath.
