测速器 meaning in Chinese

tach tachometer
velocimeter
velometer

The police officer has his radar gun to watch for speeders
交警叔叔有他的测速器，以观察车辆的速度。
Prosecutors in the belgian capital , overwhelmed by the number of speeding fines imposed since fixed radar traps were installed , have asked police to let off all but the worst offenders - - angering local mayors
自从比利时首都布鲁塞尔设置固定式雷达测速器后，检察官被堆积如山的超速罚单压得喘不过气来，因此要求警方除对犯行最重的驾驶开罚外，不要对其他超速驾驶开单这让区长们大为光火。