Phone: 253-927-6186

Ayres 875 Fluidized Calibration Bath. Temperature range 50° C to 700° C.
The AYRES Model 875 fluidized calibration bath out performs dangerous salt baths in all respects:
wider temperature range, less hazardous and better uncertainties.
This is the only product capable of covering a very wide temperature range without a change of thermal media.
Like most fluidized bed baths, the AYRES Model 875 fluidized bath consists of a container of aluminum oxide
powder with a porous base plate. Sufficient air is passed through the base plate to motivate the powder into
a fluid like state so that it will flow, display buoyancy effects and have good heat transfer characteristics.

Fluidized Calibration Bath

Model  Description 
875   Fluidized Calibration Bath Temperature range 50°C to +700°C
The Isothermal Technology Limited patented fluidized bath is the result of 20 years research and
development into flow patterns, powder technology and filtration.
Recent developments have enabled the baths facilities to be extended even further, it is now eminently
suitable for Liquid in glass thermometer calibration.
To achieve this the filter and exhaust system were re-designed to cope with the increased level of powder
needed for Liquid in glass thermometer calibration.

The result is a calibration system to national standards. The performance is only matched by heat pipe
technology. The profiles are so small that the bath has been used by National Laboratories for fixed points
of Indium through Aluminum, with great success.
In comparison mode 2 sigma uncertainties of ± 0.020° C at 300° C and ± 0.035° C at 660° C can be obtained.
A disadvantage of many fluidized-bed baths is that good temperature stability and uniformity cannot be
achieved in the fluidized medium itself.
They are obtained by using large metal blocks or by inhibiting the fluidizing action in the powder
around the work piece — either locally, or by completely collapsing the bed at the required temperature,
this is not the case with the AYRES Model 875. A full evaluation report is available upon request.

875 Ayres Calibration Bath.
Temperature Range  50° C to 700° C
Accuracy  Using freeze point cells: ± 0.0005° C to ± 0.004° C
Using comparison calibration: ± 0.020° C to ± 0.035° C 
Working Volume  67mm dia. x 475mm deep 
Heaters  3 x 1 kW 
Power  3kw, 208-240VAC, 50/60Hz 
Warm Up Time  From 50° C to 700° C, 240 minutes 
Supply Air Pressure Less than 1 BAR 100 liters/minute max
Communications  Supplied as standard with serial interface,
PC adapter cable and Cal Notepad. 
Safety  Safety melting fuse. Blocked filter cut-out
Low flow indication. Elapsed time indication.
Over pressure diaphragm 
Dimensions  Overall Height:
1570mm 880mm (to top of body) x 640mm x 580mm (HxDxW) 
Weight  Fluidizing Medium 48.5 lbs (22kg)
Overall Approx. 187.4 lbs (85kg) 
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Hotek Technologies, Inc
tel: 253-927-6186