Frequently Asked Questions


What is PPR?

PPR stands for Pipe Penetrating Radar. It is the in-pipe application of Ground Penetrating Radar (GPR), a non destructive technology to map pipe wall and bedding material conditions.

What is the difference between PPR and GPR?

GPR is mainly used from the surface to image the subsurface. In conductive soil conditions the GPR signals are unable to reach their targets. PPR on the other hand is deployed inside the pipe and will always work in non-ferrous pipes irrespective of the soil conditions around the pipe.

What is the difference between PPR and a visual inspection (CCTV)?

CCTV is only a visual assessment of the pipe. It can not determine the remaining wall thickness, potential voids developing outside the pipe, or rebar cover in RCP, for example. PPR has the ability to see beyond the inner surface.

Can you find voids?

Yes, unless the electrical properties of the filling material are exactly the same as those of the surrounding soil which is very rare.

Can you measure pipe wall thickness?

Yes, the pipe wall thickness is measured with high a 95% - 100% accuracy.

What material can PPR inspect?

  • Reinforced Concrete Pipes (RCP)
  • Vitrified Clay Pipe (VCP)
  • Brick Pipe
  • Asbestos Cement Pipe
  • Concrete Pipe
  • High Density Poly Ethaline
  • Polyvinyl Chloride Pipe
  • Wood Stave Pie

SewerVUE developed an Asbestos Cement Pipe Scanner for 10 to 18 inch pipes. The ACPS can deploy pipe penetrating radar and CCTV.

We tried GPR from the surface and it did not work. Will PPR work?

In conductive soil conditions the GPR signals are unable to reach their targets. However, pipe penetrating radar allows for condition assessments of buried pipes. PPR is deployed inside the pipe and will always work in non-ferrous pipes irrespective of the soil conditions around the pipe.

Does your system have a CCTV camera?

Yes. The SewerVUE Surveyor is equipped with three cameras. A high definition (HD) pan tilt zoom camera is used for recording the pipe during the survey for visual inspection. The other two are used to monitor the antennas and the tether.

Does it have other measuring tools?

Yes, it has a laser range finder that can measure the internal profile of the pipe and can provide quantitative information about pipe wall loss or ovality. Two inertial units are mounted onto the Surveyor. They are used to get xyz positions. Other sensors can easily be added (e.g. temperature, gas detector, etc.).

What is the maximum speed of the data collection?

PPR data collection is continuous together with CCTV and laser, the maximum speed is 30ft/min (10m/min).

What is the accuracy of PPR?

A quarter of the wavelength, on the order of a few millimetres or a quarter of an inch.

What is the maxium signal penetration?

The maximum signal penetration depends on the material the signal penetrates through. The maximum depth is usually around 12” (30cm) to 48” (120cm) from the internal surface of the pipe.

Can you do 45° or 90° bends?

The robot is capable of turning in 45° bends for the 90° bend a man entry assistance is needed.

What pipe size can you do?

The SewerVUE Surveyor is configured to inspect pipes between 21” and 60” diameter. With modifications the range can be extended. Larger diameter pipes can be inspected via manned entry.

What is a pilot project?

The pilot project is a live demonstration of the PPR technology where the client can see the process of the inspection of a chosen pipe. It typically lasts a whole day with one or two insertions during which 800-1000 ft of pipe is surveyed. Results are delivered within four weeks of the field survey.

How much can inspect in a day?

Depending on site conditions, and the layout of the pipe, SewerVUE can approximately inspect one kilometre per day (700-1000m).

What do you need for deployment and field support?

A tripod with minimum of 400lbs (180kg) lifting capacity, a generator for power supply and a 3 man crew that can provide traffic control and assistance with the insertion of the robot.

Can you go through a standard manhole?

Yes, the robot was designed to go through a standard 22.5 in manhole.

What is the method of the deployment of the robot?

The robot is lifted using the tripod and then lowered down into the manhole. In some situations man entry might be needed in order to properly position the robot into the pipe.

What clock positions can PPR antennae scan?

The PPR antennae can only collect data from the position of 9 o’clock to 3 o’clock. An additional antenna can be customized to collect data from the invert.However, Pipe corrosion due to hydrogen sulphide always attacks the crown of the pipe.

Why do you only scan the top half of the pipe?

Pipe corrosion due to hydrogen sulphide always attacks the crown of the pipe.

Can you measure rebar cover?

Yes. PPR can measure rebar cover with high accuracy.

Will it work under water?

PPR antennas work under water, however, depending on the platform used, some robotic operated vehicles can not.

How much flow can you have in the pipe?

One quarter to one third.

How much does it cost?

Please call 604 421 0600 for a quotation.

Can you do a 48” pipe?

Yes, the robot can reach up to 60"

How long is your cable?

The standard tether is 1500 ft (500 m) and the maximum tether length is 6000 ft (1850 m) for long range inspections. SewerVUE’s demo reel is 500ft (150m) long.

Who has used the PPR before and where?

PPR was used by the following municipalities: King County, WA; Atlanta, GA; Salt Lake City, UT; Stockton, CA; Palm Desert, CA; Paris, France; Portland, OR; Port Moody BC, Canada; Metro Vancouver, BC, Canada; Denver, CO; San Francisco, CA and Worthington, MN.

What is the strength of the power cable?

The pulling capacity of the power cable is 400lbs (180kg) and the breaking capacity is 3800 lbs (1700kg).

Is your robot connected by wire or wirelessly? How is it operated?

The robot is tethered, that means it is powered from and connected to the surface providing continuous data feed (CCTV, Lidar, sonar, PPR, etc.) during inspection. It is also operated from the surface (inspection vehicle) just like a normal CCTV camera.

Can I use radar to explore and monitor oil and gas pipes?

We have high definition cameras and the most accurate Lidar sensors so we can measure cracks and other defects in any type of pipe. The robot is built in such a way that we can integrate other sensors on demand. With that being said, PPR will only work in non-ferrous pipes (concrete, reinforced concrete, vitrified clay, plastic, HDPE, etc.), so most oil and gas pipes are not suitable for PPR.

Does it have a positioning system?

The robot is equipped with an on-board positioning system (IMUs), so it can map x, y and z coordinates.

Can it be deployed in security /defence applications?

It can be deployed in security and/or defence applications.