The development of pressure transmitters has broadly progressed through four distinct stages:
(1) Early pressure transmitters employed large-displacement operating principles-such as mercury-float differential pressure gauges and diaphragm-capsule differential pressure transmitters. These devices were characterized by low accuracy and a bulky physical form.
(2) In the 1950s, force-balance differential pressure transmitters emerged, offering slightly higher accuracy. However, they suffered from weak feedback forces, complex structures, and relatively poor reliability, stability, and vibration resistance.
(3) By the mid-1970s-driven by the advent of new manufacturing processes, materials, and technologies (particularly the rapid advancement of electronics)-a new generation of displacement-type transmitters appeared. These devices were distinguished by their compact size and simplified structural designs.
(4) The 1990s witnessed a rapid surge in scientific and technological progress. Transmitter measurement accuracy improved significantly, and the technology began a gradual evolution toward "smart" capabilities. Digital signal transmission became prevalent, greatly facilitating data acquisition. This era saw the emergence of various distinct types of transmitters, including diffused silicon piezoresistive, capacitive, differential inductance, and ceramic capacitive models.
(5) With the arrival of the 21st century, the third generation of transmitters-digital smart transmitters-gradually came to the forefront. Representative products of this generation include Rosemount's 3051S series, ABB's 2600T/265 series, and Yokogawa's EJX series. By incorporating advanced sensing technologies, these third-generation transmitters effectively eliminate the adverse effects of moisture, dust, and other harsh field conditions on measurement accuracy, thereby achieving higher precision. Furthermore, they boast a stability rating of five years or more, support a comprehensive range of communication protocols, and-in the case of newer models-have obtained safety certifications, ensuring a safe system shutdown should process conditions exceed critical thresholds.