單項(xiàng)選擇題當(dāng)流量在0.5L/min時(shí),用皂膜流量計(jì)校準(zhǔn)系統(tǒng)流量,相對(duì)偏差應(yīng)不大于()

A.±2%
B.±3%
C.±4%
D.±5%