Q: What types of pipes can TPA be used to inspect?
A: TPATM can inspect the following  types of mains provided they are full of fluid and pressurized to at least 5 psig / 35 kPa / 0.35 bar:

Cast Iron (CI)
up to DN 600
Stainless Steel
up to DN 450, leak detection up to DN 600
Spun Iron (SI)
up to DN 600
Ductile Iron (DI)
up to DN 600
Asbestos Cement (AC)
up to DN 450, leak detection up to DN 600
Acrylonitrile butadiene styrene (ABS)
up to DN 280
Polyethylene (PE)
up to DN 280/315 depending on SDR
Polyvinyl chloride (PVC)
up to DN 280/315 depending on SDR
Prestressed concrete cylinder pipe (PCCP)
Leak Detection Only

Q: How long a section of pipe can be inspected at one time?
A: For ferrous and asbestos cement pipes, up to 500 m, but we recommend distances of 100-200 m for optimum accuracy.  For plastic pipes, 150 m or less is best for condition assessment, although leak detection is possible at longer distances.  A two to three person crew can typically inspect between 1.2 and 1.8  km per day.

Q: How short a section of pipe can be inspected at one time?
A: 10 m, however, 25 m is recommended for better accuracy, particularly for wall thickness measurements.

Q: What type of sensors does TPA use?
A: Ceramic-shear accelerometers with a sensitivity of at least 10,000 mV/g for standard applications with higher sensitivity units used for some pipe material/diameter combinations.

Q: Does TPA use ultrasound?
A: No.  TPA’s sound sources generate low frequency tones under 5,000 Hz.

Q: How accurate is TPA‘s leak detection?
A: Field tests of simulated leaks have shown the ability to detect leaks of well under under 3 L/min at distances of at least 200 m.  Nominal leak detection accuracy for ferrous pipes is ±2 pipe diameters 9 times out of 10 for measurement distances under 350 m with a false positive rate ranging from 1 in 40 to 1 in 50 depending on pipe diameter and background noise levels.