Which of the following meters is not associated with viscosity:
Try it first: pick an option, then read the explanation.
Correct answer: D. Orsat
Asked in SSC JE 4 MARCH 2017 Morning Shift
Detailed Explanation
Various specialized viscometers measure fluid viscosity empirically by timing liquid drainage through calibrated orifices.
Why “Orsat” Is Correct
The Orsat apparatus is used in chemical and thermal engineering to analyze the volumetric composition of combustion flue gases (CO₂, O₂, CO), having no association with viscosity measurement.
Why the Other Options Are Wrong
- A. Redwood: Redwood viscometer measures kinematic viscosity in Redwood seconds (used in UK).
- B. Saybolt: Saybolt viscometer measures viscosity in Saybolt Universal Seconds (SUS, used in USA).
- C. Engler: Engler viscometer measures viscosity in Engler degrees (used in continental Europe).
Key Point
The Orsat apparatus measures flue gas composition, not viscosity.
Key Concepts for Students
- Redwood, Saybolt, and Engler are efflux viscometers that measure the time for a fixed volume to drain.
- Efflux time is converted to kinematic viscosity using empirical correlation formulas.
- Orsat apparatus uses selective liquid chemical absorbents to measure gas percentages.
Practice more: this is question 78 in Properties of Fluid MCQs – Part 6. Try the whole set and check every answer instantly.