SEM Sample Holder Custom Made to Your Choice! The Sample Holder is perfect for keeping all important SEM test specimens together. All specimens can be individually and easily removed at any time for use. The brass sample holder is 50mm diameter x 8mm thick and comes in MAC’s standards presentation box. It accommodates the following: – A 25mm or 32mm diameter x 5mm thick brass block containing your Analytical Standards, or other smaller sizes if required. – Duplex Brass Single Standard Used for checking the contrast efficiency. – Ni/Cu B.S.D. Single Standard. – Faraday Cage For measuring the current of the beam at the specimen plane. – E.D. Test Standards Three standards of your choice for E.D. test set up of calibration center. – Magnification Calibration Standard Used for magnification calibration and assessing image distortion. – Resolution Standards High and Low resolution standards for checking the performance of the S.E.M. under high resolution conditions.