Parts are available in frequency ranges of 0.25 to 5 cy/mm, 2.5 to 50 cy/mm, and 25 to 500 cy/mm. The T-61 is offered on four standard materials; Chrome onGlass (CG) Chrome on Opal (OP) Photo Paper (RM) and Film (TM). The -2 and -3 variations are only available on CG and OP consistent with their required resolution.
Equivalent cycles increase logarithmically; with two full cycles in each range. Ideally suited for scanning and micro densitometry. Each group of 2 bars and 2 spaces is progressively smaller in size.