Does Low Resolution Compromise Measurement Accuracy?

[Arm_Chair_QB]

Resolution is the smallest change that can be measured by an instrument.

Accuracy is the closeness of a measured value its 'true' value.

Precision is essentially related to repeatability when you try to do the same measurement a few times.

Forget precision for now. We know the terms resolution and accuracy mean different things and have different definitions. But that is not to say they are not related/coupled where one influences the quality of the other?

Is it true to say a low resolution instrument affects the accuracy with which you report a value. Say a beaker has increments of 0.1ml and you read off 2.3ml to your best of your ability, but while only God truly knows its really 2.2641ml exact. It is ultimately the resolution affecting the accuracy of the value being reported? So when someone reports 2.3ml it is inaccurate.

So essentially, is it true to say resolution of measurement almost always affect accuracy?

 

[mikeph]

It depends on the type of error- if there is a human reading off values, then there may be some systematic error involved, which would affect accuracy. On the other hand, if there are no systematic errors, then I would think that resolution only has an impact on the precision.

 

[CWatters]

I believe it affects both accuracy and precision.

Just for info... many years ago I was told that humans are quite good at estimating the correct value and can typically do so to within 1/10th of the scale provided. eg So in your example even though 0.1ml is the smallest scale on the beaker it might be possible to estimate the contents to about 0.01ml, although I suspect there are many qualifications that apply to this rule.