172-868-11A-QMS Mitutoyo PH-3515F Optical Comparator w/QM-Data & StandMitutoyo PH 3515F Optical Comparator Package Mitutoyo's PH 3515F is a heavy duty, bench top optical comparator that uses a horizontal optical system. This optical comparator includes an 8" x 4" floating type workstage that incorporates linear scales for fast, accurate measurement. The workstage provides high accuracy and can handle a workload of up to 100 lbs. The PH 3515F offers a 14" diameter screen that includes cross hairs for easy alignment and