YokoGawa Pressure Transmitters
ABB Pressure Transmitters
E+H Pressure Transmitters
WIKA
HoneyWell Pressure Transmitters
Micro Motion Coriolis
Rosemount Flow Meters
YokoGawa Flow Meters
E&H Flow Meters
- Measurement Point (Primary Point) ✅ Refers to a point in a detection or control system that is in direct contact with the process medium. Examples include pressure tap points in a pressure detection system, and installation points for thermocouples or resistance temperature detectors (RTDs) in a temperature detection system. A primary point may be located on a process pipeline or on process equipment.
- Primary Component (Source Component) ✅ Typically refers to the instrument fitting installed at a primary point, such as a pressure tap nipple in a pressure detection system, or a temperature well in a temperature measurement system.
- Primary Valve (Pressure Tap Valve) ✅ Refers to the valve installed on a primary component, such as the valve connected to a pressure tap nipple in a pressure detection system, or the valves connected to the upstream and downstream impulse lines of an orifice plate.
- Primary Element (Sensor) ✅ Refers to an element installed in the field that comes into direct contact with the process medium, such as thermocouples, resistance temperature detectors (RTDs), etc.
- Primary Instrument ✅ A type of field instrument that is installed on-site and in direct contact with the process medium. Examples include Bourdon tube pressure gauges, bimetal thermometers, and differential pressure transmitters.
- Primary Calibration (Unit Calibration) ✅ Refers to the calibration of an instrument before installation. According to the requirements of the “Code for Construction and Acceptance of Industrial Automation Instrumentation Projects” (GBJ—86), in principle, each instrument must undergo primary calibration.
The key aspects of calibration are inspecting the instrument’s indication error, hysteresis error, and for regulating instruments, errors in proportional band, integral time, derivative time, control point deviation, and balancing. Only instruments that meet the design or product manual requirements after primary calibration can be installed, ensuring the quality of secondary calibration. - Secondary Instrument ✅ Refers to the general term for instruments whose display signals do not directly come from contact with the process medium. The input signal for secondary instruments is typically a standardized signal converted by a transmitter.
Secondary instruments generally accept three types of standard signals:
🔶 Pneumatic signals
🔶 Type II electric unit combination instrument signals
🔶 Type III electric unit combination instrument signals - Field Instrument ✅ The general term for instruments installed on-site, including all primary instruments as well as secondary instruments installed in the field.
- Secondary Calibration (System Calibration, Loop Calibration) ✅ Refers to the inspection of the entire detection loop or automatic control system after the field installation of instruments is completed, the piping and wiring in the control room are finished and verified. It is also a comprehensive calibration before the instruments are officially put into use.
The calibration method typically involves applying a signal at the detection point and carefully observing whether each instrument in the system operates within the allowable error range. If it exceeds the allowable error range and the cause cannot be identified, all instruments in the system must be recalibrated. - Instrument Fabrication Parts ✅ Refers to the general term for all metal and plastic machined parts used in instrument installation. These parts play a special role in instrument installation.
- Piping and Instrumentation Diagram (P&ID) ✅ Refers to a drawing that describes the content of production process automation using process detection and control system design symbols.
It details the installation locations of instruments, serves as an important drawing for determining primary points, fully reflects the automation scheme and level, and serves as the basis for automation design. It is also used as a reference during construction, installation, and production operations.
Share 12 common instrument terms—do you know them all?
20
Jan
