Measuring Height of Meniscus in Capillary Action

Click For Summary
SUMMARY

The discussion focuses on measuring the height of the meniscus in capillary action, specifically referencing Jurin's Law, expressed as h = (2σ cos φ) / (rρg). It clarifies that the height measured is the difference caused by capillary action, not the absolute height from the bottom of the tube. The participants debate the appropriate point of measurement for the meniscus, noting variations based on whether the meniscus is concave or convex, and emphasize the importance of measuring at eye level for accuracy.

PREREQUISITES
  • Understanding of Jurin's Law and its formula components
  • Familiarity with the concepts of concave and convex menisci
  • Basic knowledge of fluid dynamics and surface tension
  • Ability to interpret scientific diagrams related to meniscus formation
NEXT STEPS
  • Research the implications of surface tension on capillary action in various fluids
  • Study the effects of tube radius on the height of the meniscus
  • Explore experimental methods for measuring meniscus height accurately
  • Learn about the applications of capillary action in real-world scenarios, such as in soil moisture retention
USEFUL FOR

Students and researchers in physics and chemistry, fluid dynamics engineers, and anyone studying the principles of capillary action and fluid behavior in narrow spaces.

Cogsy
Messages
1
Reaction score
0
Member advised to use the homework template for posts in the homework sections of PF.
I've been reading up on capillary action in a tube, and I have some questions:

  1. Say we insert a tube in a pool of fluid; Jurin's Law expression is ##h=\frac{2\sigma \cos \phi}{r\rho g}##. However, this height is not the height of the fluid measured from the bottom of the tube, but rather the difference in height produced by the capillary action. So, if a magical fluid had somehow no surface tension, there would be no height difference between the liquid inside the tube and the one outside of it, am I correct?
  2. From which point in the meniscus do you measure said height? I've seen some authors draw the line up to the curved edge, others to the points where the meniscus makes contact with the tube, and some even do it in between. Also, does said point vary depending on whether the meniscus is concave or convex?
 
Physics news on Phys.org
The idea is to determine the surface level of the fluid in the center of the container where it's essentially not influenced by the capillary action at the wall surface. So you read the lowest edge of the meniscus as viewed with your eye at the same level (for a concave meniscus).

The Wikipedia article on the meniscus has a reasonable overview.
 

Similar threads

Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
6K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 29 ·
Replies
29
Views
4K
  • · Replies 7 ·
Replies
7
Views
14K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 1 ·
Replies
1
Views
7K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 8 ·
Replies
8
Views
4K