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Rate Table Environmental Testing

Devices often require testing under a wide range of environmental conditions. Since many of the components within a table cannot tolerate widely varying conditions, the technique used is to extend the spindle through a thermally insulated tube to place just the platen (and therefore the test package) within the environmental chamber.

The extension tubes are designed to have a high torsional stiffness, low thermal conductivity.

Cranfield Precision uses a custom designed extension tube comprising a stainless steel housing and polymer concrete core (eg Granitan). The result is a highly damped, stiff, stable and thermally insulating extension tube.

The new tube will hold a 200C differential for over two hours, with a reduction in system bandwidth of only about 30 percent.

For long period soak testing at low temperatures, the lower end of the tube can be fitted with thermostatically controlled heaters.

A zero friction seal between the chamber floor and the rotating tube is achieve using a double labyrinth seal, one at the top and one at the bottom of the tube, with a slight negative pressure on the exhaust between them.

Rate Table Environmental Testing

Rate Table Environmental Testing