| 词条 | Optical square |
| 释义 |
}} The optical square uses a pentaprism to reflect and refract a beam or sighting 90 degrees, it is used in pairs in surveying and in a singular block in metrology. MetrologyUsed with an autocollimator or angle dekkor and mirror it can be used for machine tool axis squareness checking. For measuring the squareness of surfaces. It has two mirrors with 45 degree to each other. One is half silvered called horizon glass and other is full silvered called index glass.It measures angle by reflection. Two prisms can be used as an optical square. Optical square in surveyingIn surveying it is used both as a hand held tool for sighting between two poles (often with a plumb bob hung from the handle) and also mounted on a Jacob's staff. References 3 : Metrology|Surveying instruments|Historical scientific instruments |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。