Silver nano particles (Ag NPs) with narrow size distribution were derived chemically by sol-gel process and characterized by XRD, and highresolution transmission electron microscopy (HRTEM) techniques to confirm their formation, morphology, particle size and distribution properties. The variation in size of as prepared Ag NPs were monitored periodically every month by HRTEM for the last six months to check the stability of nanoparticles with time to assign the shelf life of Bhartiya NideshakDravay (BND) and estimated the overall expanded uncertainty in size of nanoparticles. The traceability of the developed silver nanoparticles will be derived from the NIST standard reference materialor from other NMI which established facility for assigning particle size. Such Ag NPs BNDs of different particle sizes can be used for calibration of instruments like TEM/HRTEM and particle size analyzersfor research and find usagein many industrial applications with global acceptance.

Keywords : Silver nanoparticles, Sol-gel, Uncertainty measurement, HRTEM, Particle Size analyzer.