29/01/2025
Let’s talk Quality Levels! So quality levels are those letters inside circles that you see on locator markings. No, Jerry. The communications cables are not copy-written. So there are Four quality levels with Utilities locating as per the Australian Standard and here’s what they mean.
Quality Level A – You have visually identified the service and taken measurements to show depth from surface. You got this!
Quality Level B – You traced this service by putting your own signal frequency into the service via signal induction and traced to a known point. Locating to a QLB carries margin of +/- 300mm for position and +/- 500mm or depth. Recommend NDD for more exact measurements.
Quality Level C – You can see Surface Identifiers (like hydrant points or stop valves in the case of a water main) which show alignment of service. Although depth cannot be attained from a quality level B scan, Ground Penetrating Radar currently falls under this quality level. If you see something marked as a quality level C but shows marked depth, it has most likely been done with Ground Penetrating Radar. Australian standards supersedes this however. So if you see a QLC just know you can’t guarantee the accuracy of the depth as far as the Australian Standards are concerned.
Finally we have Quality Level D – Location without Confirmation. This quality level essentially means that position of service was marked directly from service plans. Although these sometimes include measurements and offsets, no data is obtained to confirm presence or position of asset. In essence, D stands for Don’t Know.
