# HSM8 Compression of Springs

Springs are used in engineering to store energy or to provide restoring forces. Both compression and tension (extension) springs may be encountered. The deflection of a spring depends on the load applied to it, an observation enshrined in Hooke's Law (Within the limit of proportionality, the strain is directly proportional to the stress producing it).

Applications of springs are found in spring balances which indicate loads by measuring spring deflections and in car suspensions where they absorb energy caused by wheel vertical movement due to potholes and bumps.

A steel, powder coated wall housing is mounted to a rigid vertical support. A compression spring with industry standard ground ends rests flat onto the lower inner horizontal surface of the housing. At the upper end of the spring, rests a profiled boss attached to the load hanger. The profiled boss has a chamfered face thus ensure central location of the spring during loading and caters for other diameters of springs also.

An integral compression scale is attached to the wall housing. This gives an accurate indication of the compression being applied to the spring. A compression indicator is attached to the shaft of the load hanger. This has a horizontal reference line to ensure the compression can be read off the compression scale. The indicator can be adjusted up and down the length of the load hanger to adjust the start position of compression and also to cater for different lengths of compression spring that may be used.

The load hanger has a solid base to allow safe suspension of the calibrated weights supplied with the apparatus.

Students measure the compression of the spring at each load interval used. From these results recorded, a graph of load versus compression is drawn and the spring rate calculated. An alternative method given to the student is for them to measure the key dimensions of the spring and mathematically calculate the spring rate using formulae provided.

A comprehensive instruction manual for student and lecturer is provided along with a 2 year warranty.

• Determination of spring stiffness
• Wall mounted compact unit to test springs up to 200mm long and 38mm diameter
• Single compression spring supplied
• Load applied to spring using calibrated weights set and hanger
• Integral compression scale
• Adjustable compression indicator
• Optionally available HSM8a spring set (sold separately)
• Technical manual for student and lecturer provided
• 2 year warranty
•  To test the relationship between the load applied and the change in compressive length of a spring (Hooke's Law)
• To determine spring stiffness using measured experimental results and formulae provided
• Load versus compression graphs
• Action of springs
• Using the optionally available compressive spring set HSM8a (sold separately), the dependence of spring stiffness on the wire diameter, spring diameter, length, number of turns and material can be observed and calculated
• Comparison with theoretical estimate and manufacturer’s data.