A 21 cm by 8 cm, double-sided, Reflectometer and Mismatch Error calculator. This cardboard-based slide rule was used to calculate mismatches between couplers, which are used to divide the signal in a radiofrequency (rf) waveguide into two other waveguides, one of which allowed measurement of the rf power. It would have been used by personnel in the Accelerator Physics Branch at Chalk River where couplers were used to measure power levels in the radiofrequency systems used to power accelerator cavities. This artifact was manufactured by Hewlett-Packard, a prominent supplier of rf instrumentation.
