The determination of lengths is a basic requirement for optimal work results. When the folding rule is not enough, finer measuring instruments help.
The most common device for measuring length is the folding rule (Folding rule). It is available in wood with or without steel spring joints and end caps and in shatterproof plastic. Loose joints, worn ends will give false readings. Even imprecise measuring scales do not allow exact measurements. Important is, that the limbs of the staff form a straight line and that all joints are engaged. You can measure more precisely with fixed rules made of wood, plastic or metal. These rods come in lengths between 300 and 1000 Millimeter.
Tape measure from the roll
Pocket tape measures made of steel are practical (to 5 m), which are relatively kink-proof due to their curved profile. Tape measures with a viewing window and a second scale allow you to take internal measurements. Some measuring tapes roll up again by themselves thanks to a spring. There are measuring tapes made of flat steel or coated plastic fabric for measuring long distances, z.B. outside, in lengths up to 50 m.
When it comes to less than a millimeter
When working with wood, a measuring accuracy in the millimeter range is sufficient. It is different when working on metal or plastic. Tenths can do that- or hundredths of a millimeter play a decisive role. The material is measured with a caliper (Measuring stick), which has a scale in millimeters and also a vernier, where every millimeter once again in 10 or 20 areas can be divided. The reading is therefore with an accuracy of 0,1 or. 0,05 mm possible. Modern calipers with LCD digital-
are even more accurate. They can be zeroed before each measurement and measure with an accuracy of 0,01 mm.
Just as accurate, but purely mechanically you can measure with a micrometer. A fine-running spindle only shifts the measuring sensors by one revolution with each revolution 0,5 mm. A scale with a correspondingly fine division makes reading easy. External calipers can be, Within- and depth measurements up to 150 decrease mm, with a standard micrometer only external dimensions up to 25 mm. It is mainly used to measure material thicknesses.
Maintain measurement devices carefully
Calipers and micrometers are precision measuring devices. They only indicate accurately, if they are properly cared for and treated with great care. Don't you need them, wrap them in an oiled rag and keep them safe from shocks.