The EM-Tec RXS-21RE reference standard includes 21 reference rare earth elements and a 200µm aperture copper Faraday cup. All mounted in a Ø25.4 x 9mm high stainless steel 303 block. Intended as reference standard for quantitative EDS and WDS micro-analysis applications.Reference materials: LaF3, Ceo2, PrSi2, NdSi2, Sm, EuF3, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Gd3Ga5O12, Sc, Y, U, ThF4, B and C. 200µm copper Faraday cup. Preferably stored under vacuum or inert gas.