FSM-6000LEIR which is equipped with IR LED light source measures surface stress of chemically and thermally tempered glass automatically with the computer. This IR light source reduces the number of interference fringes that will be appeared on the computer display comparing to FSM-6000LE so a glass plate which has deeper stress layer can be measured by this machine.

        The computer(PC) equipped with this machine decreases measurement errors happened by each operator. Besides,complex calculation required to calculate surface stress and depth of layer for chemically tempered glass is quickly solved by the PC automatically. Data storing in PC memory directly makes quality control easily.

        Newly released FsmV software become possible to measure double ion exchanged glass in addition to thermally tempered glass and single ion exchanged glass that were applied with former software.

        Evaluation of double ion exchanged glass is easily performed because distribution of sectional stress is graphically displayed.

        Depth of stress layer is calculated based on the number of interference fringes. In deeper stress layer,counting the number of the fringes precisely tends to become less able to do because the deeper stress layer displays more interference fringes and it narrows intervals between the fringes.It is known that using a longer wavelength of light source makes the number of interference fringes decrease.(Please refer to pictures below.)

       Although,the number of the fringes appearing on the picture with 596nm narrows intervals between the fringes on the right side,in the case of 790nm,precise data are acquired because the intervals are extended according to the number of the fringes is decreased by using longer wavelength.