Glass Technology Services (Glass Technology Services) has been contracted by a Russian concern to produce a special optically pure glass containing thallium. Glass Technology Services, which developes and produces customised glasses, has revealed that its client required the optically pure glass to be free of any bubbles over 10 microns and to have no more than five per cm3 under that size. Glass Technology Services has to overcome the difficulty of retaining at least 95% of the thallium in the monovalent state. Significant transmission is lost and the glass becomes green if the thallium is allowed to move to the divalent state. Equally important for optical glasses is the homogeneity and the client has specified a delta N no higher than 0.0001, with a gradient less than 0.00005/mm. Separately, Glass Technology Services has been asked by ETSU to revise the Good Practice Guide 127 for the Energy Efficiency Office.
