We answer the most common questions asked by our customers
Can radar find plastic utilities?
Usually yes. Provided ground conditions are suitable, radar will pick up plastic utilities by detecting the interface between the plastic duct/pipe and the contents of the utility.
What diameter of utility can radar detect?
As a rule of thumb, you can detect a an object that is 10% of the depth at which it is found. So you can detect a 10cm diameter pipe at 1m depth.
What is a multi-frequency array?
This is a radar set which uses more than one detection frequency at once. Best practice for GPR surveying requires the use of 2 frequencies. Older and cheaper radar systems only have a single frequency and as such it is necessary to perform each survey twice, thus taking twice as long to do each survey.
What is PAS128?
This is the current standard for utility detection, it provides a guide to the accuracies attainable by various detection methods, the survey types suitable for different environments and applications and the standards to which surveys should be conducted. All our surveyors are fully conversant with this standard and apply it to their work.
What is the maximum depth to which you can detect a sewer?
Generally the maximum depth for tracing a sewer is 15m by the usual method of introducing a radio transmitter called a sonde into the pipe and pushing or floating it along the length requiring tracing. (The sonde can also be towed by or built into a pipeline inspection cctv crawler) For large diameter pipes there is also the option of performing a traverse through the pipe using an EDM or laser scanner in the same way as you would carry out a topographical survey on the surface. Survey stations are set up in the pipe or culvert, referenced to control stations on the surface and the pipe surveyed accurately. Although this method is very accurate it is a large undertaking as a confined space entry by several people is required. Select surveys are qualified and highly experienced in both of these approaches.
Do we work nationwide?
With our large workforce based throughout the country we can carry out survey work throughout the British Isles and internationally if so required.
Do we supply traffic management?
Yes, as most locations are traffic sensitive our surveyors are all qualified to provide basic traffic management to protect and manage their works. In addition we can provide far larger and more complex TM solutions as required on a project by project basis.
We take pride in giving exceptional service. No matter how big the project or how small the request, we strive for excellence in our response.