Poisson's Ratio of Rubber Apparatus

Product Code : EL-EAST-10415

Specifications

Slotted weights, a weight hanger and a burette for the volume method are not listed as part of the apparatus.

How the Poisson's ratio experiment is done

When a rod or tube is stretched it gets longer and, at the same time, thinner. Poisson's ratio is the ratio of the two strains: sigma = (lateral strain)/(longitudinal strain) = (d/D)/(l/L), where D and L are the original diameter and length and d and l their changes. For most metals sigma is around 0.3, but rubber changes its volume very little when stretched, so its value comes out close to the limiting value of 0.5.

In the usual college method the tube hangs vertically, is filled with water and is loaded at its lower end. For each load the increase in length and the change in internal volume are measured, and sigma = 1/2 (1 - (1/A) dV/dL), where A is the internal cross-sectional area of the tube. The small pointer fixed to the tube lets its movement be followed as weights are added.

1. Clamp the rubber tube vertically to the cast iron stand and attach a weight hanger at its lower end.
2. Fit a burette or graduated tube at the top, fill with water, and note the water level and the pointer position.
3. Add weights in equal steps and record the change in length and in water level for each load.
4. Plot volume change against length change; the slope dV/dL goes into the formula for sigma.

Key features

• Cycle rubber tube about one metre long gives large, easily measured changes
• Small pointer lets the movement of the tube be followed under load
• Heavy cast iron stand keeps the tube steady during loading
• Shows lateral contraction and longitudinal extension together
• Simple set-up for college elasticity practicals

Documentation and supply

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

Lab Exports manufactures the Poisson's ratio apparatus at its works in Laxmi Nagar, Delhi, and supplies it to schools, colleges and universities 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

• Rigidity Apparatus (Searle's Pattern) (EL-EAST-10414)
• Capillary Tube Clamp (EL-EAST-10416)
• Hooke's Law Apparatus (EL-EAST-10413)
• Rising Table with Capillary Tube Clamp (EL-EAST-10417)
• Young's Modulus Apparatus (Vernier Type) (EL-EAST-10412)
• Quincke's Surface Tension Apparatus (EL-EAST-10418)

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

Frequently asked questions

What is Poisson's ratio of rubber?

It is the ratio of lateral strain to longitudinal strain when rubber is stretched. Because rubber is nearly incompressible, the value is close to 0.5.

What is the apparatus mounted on?

The rubber tube and pointer are mounted on a heavy cast iron stand for stability during loading.

What is the price of the Poisson's ratio apparatus?

Prices are not published on the website. Add the Poisson's ratio apparatus to the Enquiry Cart with the Add To Cart button on this page, or email [email protected] with the house code EL-EAST-10415 and the quantity, to receive a quotation.

Does Lab Exports manufacture the Poisson's ratio apparatus?

Yes. Lab Exports manufactures the Poisson's ratio apparatus at its works at 11/315, Lalita Park, Laxmi Nagar, Delhi 110092, under house code EL-EAST-10415.

Request a quote

Email [email protected] with the house code EL-EAST-10415 and the quantity, or add the Poisson's ratio apparatus to the Enquiry Cart with the Add To Cart button on this page. Tender buyers can also see the Tenders and OEM page.