Many vibration tests have to be performed with a shaker combined with a climatic chamber that in the same time performs thermal and humidity cycles on the items.
The items should be mounted inside the chamber while the shaker remains outside. Sometimes the floor of the chamber is very thick and, in order to achieve this target, the armature should be reproduced inside the chamber by way of an extender.
The extender is a cylindrical fixture mounted on the shaker armature that reproduces the shaker armature inside the chamber.
The height is the main feature or the extender and is required by chamber manufacturer to match shaker and chamber heights.
The extender should be studied to be as light as possible because the mass of the extender reduces the force of the shaker that can be used to vibrate items.
The extender should also be rigid enough to not alter vibration in shaker frequency range.
The extender represents an optimal protection for the shaker from moisture compared to the use of the thermal barrier alone, but the weight of the extender usually is considered just an un-useful mass to be carried during vibration test.