Roadside shop 2-3 yuan, can I buy it? I heard that this thing will have to be tested How do you see if you have passed the test?
The 2-3 block is away, of course, one does not matter, generally more than 5 blocks can be used more for a long time, the length of 5M or above OK, as you said in Chinese detection, it is a joke, unless the accuracy of strict requirements engineering, otherwise the error within 1 cm. Can accept (mainly artificial and subjective factors), is strictly worse than other countries, not to say. If you are in the lab, the supervision company ah what use it or check it, you go to the Institute of detection is like place, not to say that you can buy to buy a standard of comparison, domestic not likely, imports of 2.30 can not buy
In the construction site, the use of general 50m is enough, like the brand is better, is all steel, quality is excellent. All steel tape measure is sold by meter, one meter per dollar. Test? Never heard of it. Small tape measure 10 yuan or so. (cheap, without good goods)
Look at the situation, if it is their own use, the store can also. If it is the project department or company, this is a measuring instrument, you need to take measurement verification, qualified in order to useGeneral 5M, 7.5M specifications of relatively easy to use. There is a "Tajima" brand is good
