纯度规格:Volumetric standard, secondary reference material for alkalimetry, traceable to NIST Standard Reference Material (SRM) Certipur® Reag. Ph Eur,Reag. USP
纯度规格:certified secondary standard reference material for pH measurement; directly traceable to primary SRM from NIST/PTB pH(S) = 4.005 (25°C) Certipur®