There are many factors in quartz component design and use conditions that can significantly impact the amount of sag in a quartz part. This calculator is a useful tool to compare the relative performance of different shapes, sizes and material types. The predicted sag may be different than actual experience, but it has proven to be a valid tool for comparison of different design features, such as rod diameter, and different materials (low hydroxyl quartz vs. high hydroxyl quartz).
This calculator can be used to estimate the amount of sag (deflection) in a horizontally supported quartz element.
Abstract:
Room temperature elastic deflection of quartz structures can be used to predict the sag in the structure at high temperature.
The difference between elastic and plastic deflection is compared and used to show that, for many structures, viscous sag is proportional to elastic deformation.
Reasonable care must be taken in handling and use to protect glass (quartz) surfaces from scratches, abrasions, pits or digs that can act as break sources. Glass under stress will fail due to a break source. Therefore, surface preparation of glass exposed to thermal or mechanical stress is critical. Alternatively, defects that are smooth and exhibit a gentle surface change are less damaging. This calculator is based on accepted strength of material calculations for the geometry and conditions selected. It assumes good workmanship in the manufacture of components. The calculator should in no way be interpreted as a guarantee or a warranty of the quartz performance. It should be used along with prudent testing of designs.
