BFS High temperature Furnace
The BFS is designed for applications requiring a constant high temperature source for calibration.
The unit which is particularly suited to long, large or irregularly shaped probes has a hinged lid and a cylindrical bath 218mm diameter by 254mm deep. 

Substantial fire brick insulation is incorporated within the outer container and the lid. Standard equipment includes a separate air supply control unit which incorporates two flowmeters for monitoring the air supply and a charge of fluidising medium (aluminium oxide) and air diffuser (zirconium oxide).

The inner container of the BFS is filled with two layers of fine granular particles. The lower layer (zirconium oxide) is denser than the upper layer (aluminium oxide) and does not fluidise but instead acts as a heat insulator. This inner container is divided into inner and outer fluidised sections to improve the temperature homogeneity within the chamber. Each area has a separate air supply which must be oil, water and dust free.

The air supply is monitored on two flowmeters in the TC-5 temperature and air flow control unit. The air supplies are adjusted to give uniform fluidisation in both sections of the bath. Heaters are mounted in firebrick insulation between the inner and outer container with the heat radiated towards the fluidised chamber.

An air extraction tube is located in a horizontal position on the rear of the bath just below the hinge on the lid. When the lid is closed, any dust created by the bath's operation can be withdrawn by connection to an extraction duct or fan.

TC-5 Controller
The TC-5 controller supplied with the BFS uses a K type chromel/alumel thermocouple which mounts onto the back of the BFS and the sensor fits into a pocket on the inner container. This unit comprises of a temperature control system and an air flow control unit. The TC-5 uses a Eurotherm controller for setting and controlling the temperature in the fluidised bath and the dual display will control and indicate the set point and bath temperature.