At present we have two ‘Structural GPR’ (Ground penetrating radar) options available for hire. GPR hire covers a wide range of applications. Our units are designed for concrete analysis in structures.
The PS1000 is manufactured by Hilti. It is designed to detect objects in concrete to a depth of approximately 300mm. This can include reinforcing bars, cable ducts, tendons, voids and back wall. Back wall (or slab thickness) is only achievable if the concrete is less than 300mm thick.
It is fitted with a 2.0GHz transmitter for detecting objects in concrete. With radar technology the larger the GHz rating of the transmitter the shallower the penetration depth and greater the detail of the result. This can present a problem for users who would like an understanding of deep embedded objects. This unit is not to be confused with the Hilti Ferroscan. The Ferroscan is a covermeter, solely to be used to detect reinforcement in concrete. The GPR equipment should not be used to determine rebar diameter.
PS1000 GPR Pros
- Our kits come complete with the PS1000 scanner, monitor and all ancillaries to conduct a survey
- Multiple scanning modes (Image scan, quick scan and quick scan recording)
- Easy to use
- Excellent and well established software for use on site and to install on a PC/Laptop
- Clear and easy to interpret results
- Original software is free of charge
- Can be paired with the Hilti Ferroscan to determine specific rebar details
PS1000 GPR Cons
- Somewhat limited scan depth
- Expensive to buy
- Latest iteration software is expensive
- Hilti update the monitor hardware (Can be confusing and over complicated)
Proceq GPR Live
The GPR Live is manufactured by Proceq in Switzerland. Again it is designed to detect objects in concrete structures. It will penetrate to a depth of 700mm in concrete. Proceq have manufactured their own ‘Ultra Wideband’ stepped frequency transmitter. This varies the detection frequency from 0.2 GHz to 4.0 GHz. It covers a useful spectrum for analysing concrete. It is this stepped frequency that allows the unit to detect from surface level down to a maximum of 700mm.
The unit is groundbreaking because of this, it can save the user large amounts of money and time on site. In general to cover this wide spectrum, multiple antennas would need to be purchased to use with rival GPR units at significant cost.
GPR Live Pros
- All in one ‘Stepped frequency’ antenna
- Utilises Ipad high resolution display for result viewing
- Software is simple to use and is a free Ipad app
- Two scanning modes (Line scan and area scan)
- Wireless connection to Ipad
- Frequent app updates with new features
- Utilises ‘Augmented Reality technology’ to present a visual representation of the scanned area
GPR Live Cons
- Software is Ipad only, all annotation must be done on Ipad
- No PC software for the unit at all *(At the moment)*
- Annotated scans can only be transferred to PC in the form of a ‘snapshot’, effectively a screenshot.
- AA batteries can drain quickly
GPR Hire Overview
The two units are both straight forward to use. However with GPR the quality of the result can be very heavily dependant on the operator. The results are best viewed as GPR data which requires interpretation.
For best results the concrete must be dry and the surface of the concrete must be as smooth as possible.
Materials with a high dielectric will slow the radar wave and it will not be able to penetrate as far. Materials with high conductivity will attenuate the signal rapidly. Water saturation dramatically raises the dielectric of a material, so a survey area should be carefully inspected for signs of water penetration.
A major issue when conducting GPR surveys of concrete is metals are considered to be a complete reflector and do not allow any amount of signal to pass through. Materials directly beneath a metal sheet, fine metal mesh, or pan decking will not be visible.