This specification covers a limit for thermal residual stress in reusable annealed glass laboratory apparatus as determined by prescribed photoelastic measurement procedures. This specification recognizes that photoelastic measurements are proportional to the difference of the principal stresses. The stress limit shall be measured and calculated to meet the specified requirements.

1.1 This specification covers a limit for thermal residual stress in reusable annealed glass laboratory apparatus as determined by prescribed photoelastic measurement procedures.