The accuracy is the degree of closeness of the measured value to its "true" value. This value is generally diffined as a purcentage of the capacity of the sensor or instrument in the unit of measurement. For example, on our Centor Easy force gauge withinternal sensor, the accuracy is 0.1% FS. It means that if you have a sensor with a capacity of 100N, the accuracy of the complete gauge is 0.1% of 100N = 0.1N.
You can find this value with different spelling: 0.1%, 0.1% of the full scale, 0.1% FS (FS: Full scale), or 0.1N.