Shop

Artificial Intelligence Notice: ISA prohibits the entry of any ISA intellectual property (“ISA IP”), including standards, publications, training or other materials into any form of Artificial Intelligence (AI) tools, such as ChatGPT. Additionally, creating derivatives of ISA IP using AI is also prohibited without express written permission from ISA’s CEO. In the case of such use, ISA will suspend a licensee’s access to ISA IP, and further legal action will be considered. Please review ISA's policies for Use of AI Tools, Intellectual Property and Terms and Conditions for further information.

Important Notice: Print books are temporarily unavailable. As of 12 August 2025, print books are no longer available for purchase on isa.org, but beginning 1 January 2026, they will be available for purchase through our publishing partner, Wiley. Kindle and ePub formats are still available via the links on each book's product page on isa.org. Learn More.

  • CCST
ISA Certified Control Systems Technician (CCST) program

Certified Control System Technicians (CCSTs) calibrate, document, troubleshoot, and repair/replace instrumentation for systems that measure and control level, temperature, pressure, flow, and other process variables.

CCST question

The Reynolds Number for a flowing fluid is most affected by which of the following parameters?

A. viscosity
B. pressure
C. friction factor
D. temperature

CCST Answer

The correct answer is A, "viscosity." The Reynolds Number for a flowing fluid can be generalized as the ratio of kinetic (or inertial) forces divided by viscous forces. Although friction factor and temperature do affect inertial forces and viscosity to some degree, and therefore, Reynolds number, viscosity has the most direct effect upon the value of the Reynolds Number.

Reference: Goettsche, L.D. (Editor), Maintenance of Instruments and Systems, Second Edition, ISA, 2005.

Reader Feedback


We want to hear from you! Please send us your comments and questions about this topic to InTechmagazine@isa.org.



Like This Article?

Subscribe Now!

About The Author