ข่าวสาร

Differential pressure level measurement relies on a fixed fluid density assumption in LRV and URV scaling. When process density changes with temperature or composition, the level reading drifts proportionally. This article covers LRV/URV formulas for open and closed tanks, density compensation calculation, HART commissioning on Emerson Rosemount 3051S and Honeywell STD800 SmartLine, and diagnostic steps for systematic level offset errors in process plants.

Radial vibration monitoring protects rotating machinery from shaft instability, bearing wear, and rotor unbalance. This article covers complete setup of the Emerson Epro MMS6350 eddy-current displacement monitor, including probe gap calibration, sensitivity matching, API 670 alarm and trip setpoints, and Modbus TCP integration with Yokogawa CENTUM VP. Practical sections address vector probe installation, signal verification, common fault patterns, and the API 670 Fifth Edition annual proof test procedure.

A HART multiplexer connects dozens of field instruments to a single Ethernet port, delivering secondary HART variables and device diagnostics to the DCS without adding AI cards. This article covers mux wiring rules, poll rate calculations, Schneider Modicon M580 BME CRA 312 10 Modbus TCP configuration, Allen-Bradley ControlLogix 1756-IF8H setup, burst mode guidelines, and a 6-step fault isolation procedure for poll timeout and CRC error failures.

China's Labour Day (劳动节) on May 1st has transformed from a socialist workers' celebration into one of the world's largest domestic travel events. This article explores the holiday's origins in the 1919 international workers' movement, its 1949 recognition as a national holiday, the evolution of the 5-day Golden Week, and the massive economic impact of 295 million domestic trips generating 166 billion RMB in spending.

Partial stroke testing of ESD valves is a mandatory IEC 61511 requirement for SIL-rated safety loops. This article covers the complete PST procedure for Invensys Foxboro FBM242 DO cards driving smart solenoid valves, integrated with GE Mark VIe PSTSEQ safety logic. Topics include stroke travel limits, timing parameters, diagnostic coverage improvement, PFDavg recalculation, and audit documentation. Practical fault patterns with resolution steps are included.

Proof testing remains one of the most misunderstood practices in safety instrumented systems. This field guide covers why periodic proof tests matter for Triconex TMR systems and HIMA PES platforms, with field-proven parameters, real failure signatures, step-by-step test sequences, and IEC 61511 compliance requirements for SIL 2 and SIL 3 loops.