A spring balance (or newton meter) is a type of weighing scale. They are commonly used to measure the force exerted on an object. This force is usually measured in Newtons and is essentially the weight of an object. The weight of an object is a measurement of its mass x gravity (W=mg). Spring balancers consist of a cylindrical tube with a spring inside. One end (the top) is usually fixed to an adjuster which can be used to calibrate the device. The other end is attached to a hook on which you can hang objects. As objects are added, the spring stretches and the resultant force can be read from the scale.Many types of spring balancers are available. The more robust models tend to be the cylindrical types however many models are prone to overextension of the spring mechanism. Choosing a model which does not allow the spring to be overstretched will increase its lifespan. Ensure spring balances are calibrated to read 0N when no masses are attached before use.