It works at a much lowerfrequency than the infrared sensors, and is less affected by dust particles.
它比红外传感器的频率要低得多，而且较少受到尘埃粒子的影响。
2
A vibration that has a higher or lowerfrequency than a sound, he found, tends to skew pitch perception up or down.
频率超过或低于声音频率的震动会分别引起音高知觉的上调和下调。
3
Such a therapy may be less costly, but the major advantage of insulin Glargine remains the greater safety of a lowerfrequency of hypoglycemic reactions.