Basically one doesn't use a micrometer to meaure large distances (the name gives it away
). Tape measures for long distances (multiple metres to parts of a metre), rulers for short (part of a metre down to millimetres), engineer's ruler for more accuracy(to half a mm), then dti's. Some dti's come in tenths of a mm, some in hundredths and some in thousandths, so you, as the operator choose the relevant measuring stick! Choice depends on accuracy or precision of the measurement required.
One often need measurents in two dimensions. Easy to move a tape measure for measuring sides of a rectangle, per eg, where the accuracy required is less. But setting up to measure tiny distances moved means the measuring instrument needs to remain in position during any change in length. This means that sometimes two instruments are needed at the same time. Conclusion? Keep all four!
Sooner or later, you will need two at the same time. They are eating nothing and only need careful storage. One may get unfortunately damaged in use, or even totalled, requiring another to be purchased before further progress. One might well be attached to a stand semi-permanently and an alternative set up is required at the time.
Do you only possess one tape measure?, only one page-sized ruler? Only one pen
cil to mark a line? Thought not! Keep both of each is my advice. EDITED TO SAY PUNCTUATION, OR RATHER LACK OF, IS NOWT TO DO WITH ME, unable to set paragrahs properly at all!
Edited By not done it yet on 05/02/2017 06:52:20