Pressure Transmitter

1. Executive Summary A differential-pressure (DP) flow loop on a process line suddenly reported PV=0 and lost local display. The instrumentation team followed a “electrical chain first, then process side” approach. Measurements isolated the fault to a non-standard cable splice ~4–5 m upstream of the transmitter that had oxidized and opened the loop. After corrective […]

Differential pressure (DP) transmitters are the workhorses behind level, flow, and filter monitoring across process plants. Yet most performance problems trace back to fundamentals—mounting, impulse line routing, wiring, and commissioning. This guide distills field-proven practices so your DP devices start accurate and stay reliable. 1) How a DP Transmitter Works (Quick refresher) A DP transmitter

Reliable gauge calibration isn’t just about applying a reference pressure and writing down numbers. Accuracy class, pressure media, contamination control, elevation head, leak checks, mounting position, how you generate pressure, pre-cycling, gas thermodynamics, and even wrench torque all matter. Get these right and your results will actually reflect reality. 1) Know the Accuracy Class (and

1. Introduction In demanding industrial environments—characterized by high temperature, high pressure, strong corrosiveness, or crystallizing media—diaphragm-sealed pressure transmitters act as a critical safety and accuracy barrier. However, many users face performance failures due to subtle but crucial configuration issues, such as: Fill fluid solidifying in cold climates; Excessive capillary length causing slow response; Improper selection

1. Evolution of Regulatory Classification 1.1 Early Classification (1981–2016) The earliest relevant regulation dates back to the Safety Supervision Regulation for Pressure Vessels (Labour and Boiler Regulation No. 7 [1981]).Article 80 explicitly classified pressure gauges alongside safety valves as “safety accessories”, requiring periodic verification at least once a year. This classification placed pressure gauges in

1. Introduction Pressure gauges are not universal instruments. Selecting the wrong type for a specific medium can result in corrosion, explosion hazards, or measurement failure. This document explains the selection requirements for pressure gauges used in acetylene, ammonia, oxygen, and hydrogen sulfide-containing media, referencing SH/T 3005-2016 and related international standards. 2. Applicable Standards SH/T 3005-2016

Introduction Pressure gauges are among the most widely used instruments in industrial applications. Like any measurement device, they require periodic calibration to maintain accuracy and ensure safe, reliable operation. At its core, pressure gauge calibration involves applying a known reference pressure and comparing it with the gauge’s reading. The difference between the applied and indicated

Differential pressure transmitters with small measuring ranges are highly sensitive to environmental interference. When installed in wind-exposed areas, strong airflow can create pressure on the negative-pressure port, resulting in inaccurate readings and compromising measurement accuracy. To mitigate the influence of external airflow and environmental fluctuations, it is recommended to install a downward-facing impulse line and

Although their names differ by only one word, capsule pressure gauges and diaphragm pressure gauges are fundamentally different in structure, working principle, applicable media, and usage scenarios. Understanding their distinctions is essential for proper selection and application. ⚙️ 1. Working Principle ● Capsule Pressure Gauge A capsule pressure gauge uses a pressure-sensitive element called a

🛠 Scope of Application This procedure applies to the safe operation of differential or pressure transmitters equipped with a 3-valve manifold (comprising a High-Pressure Valve [H], Low-Pressure Valve [L], and Balance Valve [B]). Correct sequencing is essential to prevent diaphragm damage and ensure accurate pressure readings. ⚙️ Fundamental Principle Always protect the transmitter by using