Force meter
A force meter is an instrument to measure the magnitude of a force. This is often just a spring contained within a cylinder that has a scale to mark the extension of the spring produced by the force. In the International System of Units, the unit of force is the newton (symbol N). A force meter that measures force in newtons may be referred to as a newtonmeter.
Force
An alternative unit of force in a different foot-pound-second system, the absolute fps system, is the poundal, defined as the force required to accelerate a one-pound mass at a rate of one foot per second squared. The units of slug and poundal are designed to avoid a constant of proportionality in Newton's Second Law.