A precision 20Ω, 0.1%, 10ppm/°C resistor used with the SCM5B32 current input module or SCM5B42 two-wire transmitter interface module. Sockets are provided on the SCMPB01/02/03/04/05/06/07 and SCMXEV backpanels to allow installation of this resistor. One SCMXR1 is shipped with each SCM5B32 or SCM5B42 module