Quincke's Surface Tension Apparatus

Product Code : EL-EAST-10418

Specifications

How Quincke's method is used

Mercury does not wet glass, so a large quantity poured onto a clean horizontal surface forms a broad, flat-topped drop instead of spreading out. Consider the part of the drop between its flat top and the level where its side becomes vertical, at depth h below the top. The outward hydrostatic push on that vertical section, 1/2 rho g h^2 per unit length, is balanced by the surface tension T acting horizontally at the top, so T = 1/2 rho g h^2, where rho is the density of mercury.

The method only works if the supporting surface is truly horizontal; otherwise the drop spreads unevenly and the heights are wrong. That is the job of this apparatus: the three levelling screws adjust the circular plate and the sensitive spirit level confirms when it is level.

1. Stand the apparatus on a firm bench and adjust the three levelling screws until the spirit level bubble is centred in every direction.
2. Form a large mercury drop, several centimetres across, on a clean horizontal surface set on the levelled plate.
3. Measure the depth h from the top of the drop to its widest section with a spherometer or travelling microscope.
4. Calculate T = 1/2 rho g h^2 and repeat with fresh readings.

Mercury is toxic. The experiment should be carried out on a spill tray in a ventilated room under supervision, with the mercury recovered into a sealed container afterwards.

Key features

• Three-point levelling sets the plate precisely horizontal
• Sensitive spirit level confirms the level before readings are taken
• Circular metallic plate gives a stable support for the drop
• Purpose-built for the surface tension of mercury by Quincke's method
• Suits advanced surface tension practicals in college physics

Documentation and supply

Most Lab Exports products carry a one-year manufacturer warranty.

Lab Exports manufactures the Quincke's apparatus at its works in Laxmi Nagar, Delhi, and supplies it to colleges, universities and teaching laboratories in India and 60+ countries, handling the export documents for each shipment. More about the company is on the About Lab Exports page.

Related Elasticity and Surface Tension products

• Rising Table with Capillary Tube Clamp (EL-EAST-10417)
• Searle's Surface Tension Balance (EL-EAST-10419)
• Capillary Tube Clamp (EL-EAST-10416)
• Surface Tension Apparatus (EL-EAST-10420)
• Poisson's Ratio of Rubber Apparatus (EL-EAST-10415)
• Viscosity Apparatus Stokes Method (EL-EAST-10421)

The full range is in the Elasticity and Surface Tension section of the Physics Lab range.

Frequently asked questions

What does Quincke's apparatus determine?

The surface tension of mercury, from the height of a large mercury drop resting on a levelled horizontal surface.

Why are three levelling screws used?

Three screws define a plane and let the circular plate be set exactly horizontal, which is essential for a symmetrical drop and correct height readings.

What is the price of the Quincke's apparatus?

Prices are not published on the website. Add the Quincke's apparatus to the Enquiry Cart with the Add To Cart button on this page, or email [email protected] with the house code EL-EAST-10418 and the quantity, to receive a quotation.

Does Lab Exports manufacture the Quincke's apparatus?

Yes. Lab Exports manufactures the Quincke's apparatus at its works at 11/315, Lalita Park, Laxmi Nagar, Delhi 110092, under house code EL-EAST-10418.

Request a quote

Email [email protected] with the house code EL-EAST-10418 and the quantity, or add the Quincke's apparatus to the Enquiry Cart with the Add To Cart button on this page. Tender buyers can also see the Tenders and OEM page.