Important Parts of a Ground Penetrating Radar

A ground penetrating radar is a type of radar built for subsurface imaging. It is designed to see things underground as opposed to radars that are used to identify airplanes, ships or vehicles through the mediums of air and water. This technology can be used for a number of applications ranging from non-invasive archeological inspections to forensics, earth sciences, and especially useful for locating buried metals and other materials. Ground penetrating radar systems are usually comprised of three main components, namely, the control unit, antenna/receiver, and power supply.

The control unit typically contains the electronics that trigger the pulse of electromagnetic energy waves that the device’s antenna then sends into the ground. GPR systems also feature an in-built computer for processing and solid state memory or hard disk in which to store data for examination after the field survey. In other systems, the device is controlled by an attached computer with a pre-installed/loaded control software. This allows for easier data processing and interpretation on the spot, without the need for downloading radar files and findings into another computer.

The antenna receives electrical pulses from the control unit and then amplifies the signal into the ground or another surveyed medium at a specific frequency. This antenna frequency is one of the major factors affecting depth penetration. The higher the frequency, the shallower into the ground the signal will penetrate. Higher antenna frequencies, however, are capable of seeing smaller targets at depths close to the surface. Antenna choice also affects survey design.

A ground penetrating radar device can also be run using a variety of power supplies. This can range from small rechargeable batteries to larger, more powerful vehicle batteries. They can be integrated with the system using connectors and adapters appropriate for each source type. Others have small internal rechargeable batteries, but may also be connected to external power sources.

Points To Remember While Doing Slump Test

A slump test is conducted to find empirical data to measure the workability of fresh concrete. The test determines the consistency of concrete from a specific batch. Slump testing is performed on site to determine the quality of delivered concrete prior to being used. Certain points must be remembered while performing a slump test. Here are some of them:

• How testing can help determine concrete consistency – Consistency pertains to the ease of concrete flow which may affect the material’s workability and quality. Testing helps to determine the degree of the material’s wetness. Wetter concrete is more workable than a drier mix, but concrete of a similar consistency may vary in terms of workability. Doing a slump test is recommended when determining the consistency between batches, too.
• Use the right equipment – Slump tests are traditionally done with a slump cone, which is a 12-inch high right circular cone. Its base is eight inches in diameter, and the top is four inches in diameter.
• Filling the cone properly – Fresh concrete is poured into the slump cone in three layers, while making sure that each layer is of equal volume and stroked 25 times with a ¾-inch diameter rod. The rod’s end is typically shaped like a bullet.
• Revealing the slump – After filling the cone, the concrete is levelled off at the top. The cone is vertically raised to let the concrete slump or collapse. The distance where the concrete slumps or falls from the original height is the concrete’s slump, which is measured in centimetres and written to the first decimal point.
• Use advanced slump test equipment – These days, concrete is not merely a blend of three basic ingredients. It can also contain fibres, polymers, and admixtures. This could result in a coarse aggregate, which may be an insufficient factor when determining water content. Hence, a low or high slump may not accurately indicate the quality of concrete. In this case, you have the option to use modern technologies with a slump test. Make sure to look up advanced concrete testing equipment online and make sure that they are made according to AS1012, which defines the correct sampling tools, equipment, and correct procedures for testing concrete.