The NaviTrack Scout from RIDGID is the fast and easy way to locate a transmitter beacon, or sonde, like the one in a SeeSnake camera system. In this tutorial we’ll show you how to quickly pinpoint the sonde’s position underground. We’ve pushed our camera a few feet into a drain line and we’ve activated its sonde, so lets get started. We’ll power the receiver ON. Then we’ll use the frequency key to select 512Hz sonde mode. We want to hear the receiver’s audio feedback while we’re locating, so we’ll use the Volume key to turn the sound up. We’re going to demonstrate a simple three-step method for locating a sonde: Localize, Pinpoint, & Verify.
Localize simply means finding the sonde’s approximate location – in other words, which direction do we walk? Next we’ll Pinpoint the sonde by using Scout’s display icons to map its precise position. Then we’ll Verify our result by confirming that the signal is strongest at this location. To localize the sonde we’ll look at the signal strength on the receiver. We’re going to extend the receiver and sweep in an arc to find the point where the signal is strongest. When the signal is strongest we’ll be pointed at the sonde. We’ve localized the sonde, so let’s pinpoint its location. We’ll lower the receiver and walk toward the sonde. As we approach the sonde icons will appear on Scout’s display. These icons represent the position of targets that we can use to map the sonde’s location. There are two types of targets: Poles, which occur at each end of the sonde, and the Equator, a plane that crosses over the center of the sonde.
If you draw a line between the two poles, the sonde is located where that line and the equator intersect. We’re going to map the two Poles and then we’ll map the Equator. We’re going to center the first pole on the crosshair. For the greatest accuracy we want the receiver close to the ground, and we want to keep it fairly level. We’ve have the first pole, so we’ll drop an orange chip to mark its position. We know that the second pole is on the other side of the Equator, so we’ll walk past the Equator, and then we’ll locate the second pole. Next we’ll line the receiver up between 0 the two poles and center the Equator. The sonde should be located at this position, and we can see that it is.
We’d normally drop the yellow chip at this point to mark the sonde’s position. We’ve localized the sonde, we’ve pinpointed it by mapping the poles and the equator… Next we’ll Verify by confirming the signal is strongest at this location. We’ll do that by making sure the signal drops if we move the receiver in any direction… …And it does. We can be confident we’ve found the sonde’s location. To get a depth measurement, we’ll need to position the receiver directly over the equator. We want the lower antenna touching the ground, and we want the receiver to be fairly level. Next we’ll rotate rotate the receiver in the direction indicated by the arrow at the bottom left of the display. Then we’ll confirm our depth reading by rotating the receiver 180 degrees and taking another reading. We’ve seen how to locate the sonde by mapping the poles and the equator, and we’ve seen how to measure its depth.
If you find that the signal is highest when you’re close to a pole and drops as you move away from the pole, the sonde is tilted in the line. And when a sonde is severely tilted, you may only be able to locate one of the poles. To show you what a severely tilted sonde looks like, we’ve placed the camera into a vertical portion of pipe. We’ll center the receiver over the pole. And as you can see, the signal drops when we move away from the pole. This tells us that our sonde is tilted, and we’ll need to pinpoint its position by finding the point where the signal is strongest. When we find the place where the signal is highest, that’s where we’ll mark the sonde. When a sonde is tilted, Scout’s automatic depth feature won’t work, so we’ll need to use the Force Depth feature to get a reading. We’ll position the receiver where the signal is highest, and press and hold the Down arrow key. If the depth looks reasonable, we’ll rotate the receiver 180 degrees and take another reading.
We’re looking for the two readings to be within about 10% of one another. If they are, we can consider the depth to be accurate. If there’s more than a 10% variance we’ll want to rotate the receiver a quarter turn and take another set of readings. We’ve seen how to locate the sonde using the three step process: Localize, Pinpoint, and Verify. We’ve seen how to recognize a tilted sonde, and we’ve seen how to take a depth reading. Always remember that when locating a sonde, signal strength is the final determining factor. Now, you’re ready to locate your sondes with confidence..