Related Experiment Video
Updated: Jun 21, 2026
05:11
High-precision Electromagnetic Flowmeter with Empty Pipe Detection via Complex Programmable Logic Device-based Waveform Recognition
Published on: June 27, 2025
Development and performance analysis of a standard orifice flow calibration system.
H M Akram1, M Maqsood, H Rashid
1NINVAST, National Centre for Physics Complex, Shahdara Valley Road, P.O. Box # 3125, Islamabad, Pakistan.
The Review of Scientific Instruments
|August 7, 2009
Summary
A new indigenous orifice flow system serves as a primary standard for calibrating high vacuum gauges. This system achieves high accuracy, with combined uncertainties around 4.0 x 10(-6) mbar for vacuum calibration.
Area of Science:
- Physics
- Metrology
- Vacuum Technology
Background:
- Accurate calibration of high vacuum gauges is crucial for scientific research and industrial processes.
- Existing calibration methods may have limitations in precision and range.
- Development of primary standards is essential for reliable vacuum measurements.
Purpose of the Study:
- To develop and validate an indigenous orifice flow system as a primary standard for high vacuum gauge calibration.
- To establish a reliable and accurate method for generating and measuring pressures in the 10(-3)-10(-6) mbar range.
- To assess the uncertainty and performance of the developed primary standard.
Main Methods:
- Design and implementation of a constant-volume flow meter to generate a known gas flow rate.
- Utilizing a partitioned vacuum chamber with an orifice of calculable conductance.
- Comparison of pressures generated by the primary standard with a secondary standard (spinning rotor gauge).
- Calculation of uncertainties and correction factors.
Main Results:
- The orifice flow system demonstrated a maximum percentage deviation between 1.16% and 0.97% when compared to the secondary standard.
- Combined uncertainties for the entire calibration range were determined to be within 4.0 x 10(-6) mbar.
- The system successfully provides a primary standard for high vacuum gauge calibration.
Conclusions:
- The developed indigenous orifice flow system is a viable primary standard for high vacuum gauge calibration.
- The system offers high accuracy and reliability in the specified pressure range.
- This advancement contributes to improved precision in vacuum metrology.
Related Concept Videos
01:28Pipe Flowrate Measurement
In pipe flow measurement, orifice, nozzle, and Venturi meters are commonly used to determine fluid flowrates by constricting the flow area, which increases fluid velocity and reduces pressure. This pressure difference, governed by Bernoulli's principle and adjusted for real-world conditions, is essential for calculating flowrate. Each meter type is suited to specific applications based on accuracy, efficiency, and compatibility with various flow conditions.
The orifice meter is a simple,...
The orifice meter is a simple,...
01:28Pipe Flowrate Measurement: Problem Solving
A spray tank system is engineered to uniformly distribute a pest-control liquid across plants by using a pressurized mechanism. The tank, pressurized to 150 kPa, holds the pesticide at a height of 0.80 meters. Liquid flows from the tank through a 1.9 meter pipe with a diameter of 0.015 meters, angled at 0.698 radians, ultimately reaching a 0.007 meter nozzle that sprays the pesticide. Accurate calculation of the system's flow rate is crucial to ensure uniform application, and this is achieved...
01:16Measurement of Fluid Pressure
Fluid pressure is commonly measured using devices called manometers, which rely on liquid columns to indicate pressure differences. The height of a liquid column in a manometer reflects the pressure exerted by the fluid, providing a simple yet effective means of measurement. Different types of manometers serve specific purposes based on their configurations and the type of fluids involved.
A basic form of manometer is the piezometer, a vertical tube open at the top and filled with the same...
A basic form of manometer is the piezometer, a vertical tube open at the top and filled with the same...
01:30Typical Model Studies
Fluid mechanics model studies often utilize scaled-down systems to predict fluid behavior in full-scale environments, such as river flows, dam spillways, and structures interacting with open surfaces. Maintaining Froude number similarity in river models is crucial, as it replicates surface flow features like wave patterns and velocities.
01:12Instrument Calibration
Instrument calibration is essential for ensuring that instruments produce accurate and consistent results. It is vital in manufacturing, healthcare, testing laboratories, and scientific research. Calibration processes are specific to each instrument and help enhance data accuracy. Each instrument has a unique calibration process tailored to its design and function to improve data accuracy.
Analytical Balance Calibration
An analytical balance measures mass and requires regular calibration to...
Analytical Balance Calibration
An analytical balance measures mass and requires regular calibration to...
01:24Single Pipe Systems
In pipe flow analysis, problems are typically categorized into three types — Type I, Type II, and Type III — based on the known parameters and the desired outcome. Each type of problem addresses specific engineering requirements using fluid properties, pipe characteristics, and operational conditions.
In a Type I problem, fluid properties (density and viscosity), pipe characteristics (including diameter, length, and surface roughness), and the flow rate or average velocity are known. The...
In a Type I problem, fluid properties (density and viscosity), pipe characteristics (including diameter, length, and surface roughness), and the flow rate or average velocity are known. The...