Emerson Puts 80 GHz Radar on a WirelessHART Power Budget

Emerson has introduced the Rosemount 3408 Wireless Level Transmitter, combining 80 GHz FMCW radar electronics with WirelessHART communication and long-life power modules. It supports HART and the Field Device Integration standard. Measurement range, accuracy, power module life, update rate and SIL rating were not disclosed.

The engineering claim is in the combination rather than either half. 80 GHz radar has historically been power-hungry enough that a battery-powered wireless version was impractical; fitting FMCW electronics inside a WirelessHART power budget is the part that took work.

What it buys is an instrument with no wiring at all — no signal cable, no power cable, no conduit, no tray. On a remote tank in a tank farm, the instrument has rarely been the expensive part of a level measurement point. The trench, the conduit run, the junction box and the marshalling are. Removing them changes installed cost per point by a large multiple, and changes which measurement points are worth adding at all.

Emerson contrasts the 3408 with guided wave radar, which has to contact the process medium and is therefore harder to apply to corrosive or sticky materials. That comparison also points at the brownfield case: a non-contacting wireless instrument can be added to an existing vessel without a process connection, which means without a vessel entry, a hot work permit or a shutdown.

For anyone trying to instrument tanks that were never wired because the business case did not survive the cable estimate, that is the relevant sentence.