A measurement transmitter includes a main housing body with a first cavity closed by a first cover and a second cavity closed by a second cover. A measurement circuit assembly in the first cavity includes power and service communication conductors that extend through the main housing body to contacts in the second cavity. A replaceable module plugs into the contacts in the second cavity and includes a primary battery and a service communication connector. The service communication connector is exposed for connection to service equipment by removal of the second cover.