Fluidised Furnace Model 875

Description

Designed to deliver consistent and repeatable results, the 875 excels in comparison calibration. Its fluidised powder medium provides exceptional temperature uniformity and thermal contact—without the risks associated with corrosive salt media.

A key advantage of the Model 875 is its deep immersion capability of up to 475 mm—significantly more than dry block calibrators. This reduces stem conduction errors which is critical for high-accuracy calibration. In our own ISO 17025 accredited laboratory, we use the 875 for comparison calibration of Platinum Resistance thermometers from 300°C to 700°C, achieving uncertainties as low as ±0.020°C at 300°C and ±0.035°C at 660°C.

The system uses high-purity aluminium oxide powder, fluidised by compressed air passing through a porous base plate. This creates a uniform, stable medium with excellent heat transfer properties. Unlike many fluidised baths that rely on metal blocks or collapsing the bed to improve stability, the 875 delivers full thermal performance with the powder in flow.