What Is a Rebar Detector?
A rebar detector is a device that measures the rebar, water pipes, electrical wiring, etc., inside concrete. It is used to check the structure and construction condition of a building and to confirm whether wiring has been cut or not. If the rebar is not well connected or the wiring is not in the proper position, it could cause an accident. Inspection with a rebar detector is a very important process. It is a non-destructive way to check the inside of a structure without damaging the structure. There are two main inspection methods: the electromagnetic radar method and the electromagnetic induction method.
Uses of Rebar Detectors
Rebar detectors are used to measure the thickness of the rebar and its covering in concrete buildings. These include buildings, condominiums, and other structures, as well as ground and highways made of concrete. In addition to reinforcing bars, other items buried in concrete include water pipes, gas pipes, and electrical wiring. When constructing a building, rebar detectors are used to check for defects in the rebar and identify structural flaws. They are also used to check the internal conditions during the installation of electrical and gas piping and air conditioning equipment.
Principle of Rebar Detectors
There are two types of rebar detectors based on different measurement principles.
- Electromagnetic Wave Radar Method
This method uses electromagnetic waves to examine the interior of concrete. This type of rebar detector is equipped with a transmitting antenna to send electromagnetic waves and a receiving antenna to receive them. When electromagnetic waves are sent toward the concrete, they travel inside and are reflected by the rebar and wiring. The position and size of objects inside can be determined from the time it takes to receive the waves, including this reflection. In addition, many rebar detectors of the electromagnetic radar method are driven type with wheels, and measurement can be made while moving the surface of the concrete to enable more three-dimensional measurement. - Electromagnetic Induction Method
This method uses the principle of electromagnetic induction to examine the interior of concrete. First, a magnetic field is generated by passing an alternating current through a coil. The principle of electromagnetic induction causes an electric current to flow through the rebar, generating a magnetic flux. By detecting this change, it is possible to check the inside of the concrete. Although this method is capable of accurate and precise measurement, errors may occur if multiple magnetic materials are included in the magnetic field.