We have talked many times in this column about the advantages air gaging brings to the manufacturing process, especially on the shop floor. In addition to their speed, ease of use and ability to automatically clean part surfaces before measuring, air gages are also capable of measuring to tighter tolerances than mechanical gages. At their very best, mechanical gages can measure down to 50 millionths, but that requires extreme care. Air gages handle 50 millionths with ease, and some will measure to a resolution of 5 millionths.
    我們在Gaging Tips（測量技術(shù)）這個(gè)專(zhuān)欄里多次提到過(guò)氣動(dòng)量?jì)x在生產(chǎn)過(guò)程尤其是車(chē)間里的測量?jì)?yōu)勢：除了速度快、操作簡(jiǎn)便以及測頭的自潔能力外；相較機械量規，氣動(dòng)量?jì)x還能測量更小公差的工件；機械量規佳狀況下可測到0.00005’，但測量過(guò)程需極其謹慎小心，而氣動(dòng)量?jì)x則可輕松測到0.00005’，有時(shí)分辨率甚至可達0.000005’。

    When most people think of air gaging, they think of plugs. But a number of air ring and air fork styles provide the same benefits and some additional ones as well.
    一提到氣動(dòng)量?jì)x，大部分人腦子里浮現出的是氣動(dòng)塞規，但其實(shí)很多氣動(dòng)環(huán)規和氣動(dòng)卡規也同樣可實(shí)現或完成更多測量任務(wù)。

    An air ring is the opposite of an air plug, and is primarily used to measure ODs. Air rings look quite simple—a steel ring with a pair of jets at a particular location—but there is a lot of engineering built into them. One trick is in calculating the size of the ring in order to achieve a good balance of clearance between the part and the opening in the ring. Too much clearance and your readout will start showing centralizing error. This happens when the part is shifted slightly in the tool and the air ring measures a chord rather than the diameter. Too little clearance and the indicator's range gets limited—or even worse—a geometry error can prevent the operator from inserting the part into the air tool.
    與氣動(dòng)塞規測量?jì)葟絼偤孟喾?，氣?dòng)環(huán)規主要用于外徑測量。其外觀(guān)看上去非常簡(jiǎn)單——在一個(gè)在特定位置有一對噴氣孔的鋼圈，但其實(shí)其內部設計十分復雜。其中一項設計是用來(lái)計算環(huán)規的大小以確保工件和環(huán)規之間的間隙達到合適的平衡：間隙太大讀數經(jīng)常容易出錯，因為當工件輕微移動(dòng)時(shí)，環(huán)規測量到的數據只是外圓的弦長(cháng)而并非直徑；若間隙太小，顯示范圍會(huì )受限甚至更糟——形位誤差容易導致操作者無(wú)法將工件插入氣動(dòng)環(huán)規中。