The Techne FB-08 is an attractively finished rectangular bench standing unit. The controls for temperature and fluidising air flow are mounted on a recessed panel on the front of the unit, together with on-off switches for the power supply and the dust extractor and indicators for various functions.
Techne FB-08 Key Features
The inner container is well insulated and the outer case is vented so that it remains safe to touch even when the bath is operating at its maximum temperature. The inner container is filled from the top with alumina. When fluidised this medium is heated by four immersion heaters close to the container wall; the control thermocouple is close to the heaters. The heater elements are protected (by a pressure switch operated by the fluidising air) from excessive surface temperatures if fluidisation is lost.
Clean dry air from an external source passes through two filters and two regulators, to reduce the pressure for the cylone extraction system and for fluidisation. The fluidising air passes through a flowmeter and then to a plenum chamber from which it is distributed evenly round the inner container. Dust extraction is by means of ambient air drawn down past the probe plate and through a peripheral slot round the top of the inner container, then through a cyclone to the exhaust filter. Entrained medium, removed by the cyclone and discharged into a special jar accessible from the front of the unit, can be emptied back into the bath at regular intervals.
Sensor Calibration is simple and easy with the FB-08 series fluidised baths.
Set the bath to the required calibration temperature
Suspend the sensor to be tested in the bath (using the probe plate supplied) close to the centre of the working volume and allow the bath to stabilise for a short period.
Calibration can now be carried out using either a certificated standard (Comparison method) or the readout from the FB-08 control unit (direct method).
In operation, set the flow of fluidising air by means of a combined control valve and flowmeter. The setting will vary depending on the operating temperature; at higher temperatures a lower flow rate is required for good fluidisation.
Select the required operating temperature by depressing and releasing either the up or down button on the front panel of the control unit. The digital display will indicate the set point value for two seconds and then revert to bath temperature.
Sensors for calibration should be suspended as close as possible to the centre of the working volume. Nothing should be put into the bath which obstructs more than one third of the cross-sectional area of the fluidised medium.
Controller
Model FB-08 standard controller Eurotherm 2208L
The Eurotherm controller includes 3 term (PID) control functions, digital set and readout of the bath temperature. Power is switched via a solid state relay.
This controller has dual 4 digit display which normally shows the process variable and the setpoint.
Individual indicators show manual mode, setpoint rate limit selected and output status. A feature is the ability to 'hide' parameters to allow operators access only to the information required.
F949D FB- 08 Fluidised Bath 230V 50/ 60Hz. Excludes alumina 25kg
F0855 Alumina-white aluminium oxide, 1Kg (MINIMUM ORDER 25 x 1Kg)