The Rosemount 1151 Pressure Transmitter combined 4-20 mA electronics with capacitance sensing technology when it was introduced in 1969, and it went on to become the industry’s standard for process pressure measurement for more than 40 years. It measured differential, gauge, and absolute pressure across a wide installed base that still exists in plants today, including some legacy nuclear and process installations.

Emerson’s own product page confirms the 1151 is now obsolete. It is not offered as a new-build unit, and Emerson directs buyers to “contact your local Emerson representative for your measurement needs” rather than naming an in-line successor on that page. In practice, the documented, Emerson-published upgrade path is the Rosemount 3051, which improves on the 1151 with accuracy of 0.04 percent of span, five-year stability of 0.125 percent of URL, 150:1 rangedown, and SIL 2 safety instrumented system certification, none of which the original 1969-era 1151 platform offered.

We are being direct about this rather than listing the 1151 as an in-stock, ready-to-order product it no longer is. Instrubiz can help in two ways: sourcing remaining 1151 units or components where a plant needs to keep an existing installation running, and cross-referencing an existing 1151 to the correct 3051 replacement configuration for a planned upgrade.