The invention discloses a civil
construction engineering site reinforcing
steel bar detector, and relates to the related field of building detection. The instrument comprises an instrument body, and a protection groove and a
handle screen are arranged in the middle of the top of the instrument body. The device is provided with a
brake part, a fixing rod, a spring, a pressing column, a pressing block, a sliding groove, a sliding block, a first limiting block and a second limiting block, when the instrument is not used, a worker applies pressure to the pressing block with fingers, then the pressing column pushes a connecting plate to overcome the elastic force of the spring to move downwards, and then the fixing rod drives the
brake part to be attached to a roller; meanwhile, a worker slides a pressing block again, so that a pressing column drives a sliding block to slide in a sliding groove, a first limiting block is just clamped at the bottom of a second limiting block, a braking piece can be prevented from being bounced by
restoring force of a spring, a roller is braked through the braking piece, and therefore the
detector is not prone to rolling off when placed on a table top, and the risk that the
detector is accidentally broken is reduced.