Starting 2021, TIM will be a rapid-publication online-only volume-only journal. It is anticipated that an accepted paper will be assigned to a Volume with article sequence number in about 3 weeks after IEEE receives the correct files from the authors of accepted papers. Please note that as of January 2021, there will be no more printed Issues, or Issues at all. The last printed issue was the December 2020 Issue.
For scope and topics covered, please see TIM's scope.
TIM has a long history, and in fact celebrates its 70th anniversary in 2021. In 1952, the Transactions of the IRE Professional Group on Instrumentation was launched. Its papers can be accessed in IEEE Xplore here. In 1955, the name was changed to the IRE Transactions on Instrumentation, whose papers can also be accessed in IEEE Xplore here. IRE was the Institute of Radio Engineers, which in 1963 merged with the American Institute of Electrical Engineers (AIEE) to form the present day IEEE. Subsequently, in 1963 the name of the transactions was changed to the IEEE Transactions on Instrumentation and Measurement. You can see a history of TIM's EiCs over the years, at the bottom of that page.
Indexes (list is not exhaustive):
Science Citation Index
Science Citation Index Expanded
Essential Science Indicators
Current Contents: Engineering, Computing & Technology