datum dimension

基本解釋

If the element being tested with tolerance requirements is an axis, centre line or symmetrical plane, the arrow and datum symbol should be aligned to the dimension line of that element.
當(dāng)被測(cè)要素為軸線、中心線或?qū)ΨQ平面時(shí)，指引線的箭頭和基準(zhǔn)符號(hào)應(yīng)與該要素的尺寸線對(duì)齊。
This method realizes the 2 dimension constrained adjustment of GPS control network based on quasi-stable datum using classical adjustment of free networks and coordinate transformation method.
該方法采用經(jīng)典自由網(wǎng)平差和坐標(biāo)轉(zhuǎn)換法實(shí)現(xiàn)基于擬穩(wěn)基準(zhǔn)的GPS控制網(wǎng)2維約束平差。
If the element being tested with a tolerance requirement is a contour line or surface, point the arrow and datum symbol to the contour line or surface, and keep it away from the dimension line.
當(dāng)具有公差要求的被測(cè)要素為線或平面時(shí)，將指引線箭頭和基準(zhǔn)符號(hào)指在線或平面上，且必須與尺寸線錯(cuò)開。