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.
Coherence (units of measurement)
Isaac Asimov wrote, "In the cgs system, a unit force is described as one that will produce an acceleration of 1 cm/sec on a mass of 1 gm. A unit force is therefore 1 cm/sec multiplied by 1 gm." These are independent statements. The first is a definition; the second is not. The first implies that the constant of proportionality in the force law has a magnitude of one; the second implies that it is dimensionless. Asimov uses them both together to prove that it is the pure number one.