Locating cables and pipes: Part 2Follow
The RD7100 system supports up to four antenna modes, exclusively dedicated to locating cable and pipes, and to suit your particular application or the local environment. These are:
- Peak mode
- Peak+ mode
- Guidance mode
- Null mode
Peak mode provides the most sensitive and accurate mode for location and depth measurement. It provides a sharp Peak response with a corresponding small decrease in sensitivity. Peak mode cannot be disabled using the menu.
In Peak mode the following indicators are displayed by the LCD:
- Signal strength
To select Peak mode:
Press the key until the Peak mode icon is displayed on the LCD.
NOTE: The depth and current values will display automatically, although these values should not be considered accurate until the locator is directly over the target line.
Peak+™ mode combines the accuracy of the Peak bargraph with a choice of Guidance or Null directional arrows. Guidance arrows provide visual indication of the direction to the target utility, and are designed to get you close to the Peak position faster, before using the Peak bargraph to pinpoint the target utility. Using Null arrows allow you to check for distortion before marking a point, and should be used when accurate locate measurements are required.
Switching between arrow types:
When in Peak+ mode, press and hold the key to toggle between Guidance and Null arrow types.
You can also select the default arrow type in the locator menu:
- Press the key to enter the menu.
- Scroll to the ARROW menu using the orkeys.
- Press the key to enter the ARROW menu.
- Select NULL or GUIDE using the or keys.
- Press the key twice to return to the main locate menu.
When using Guidance arrows:
Use the proportional arrows to guide the locator along the path of the target cable or pipe. To accurately locate the center point of the target utility, for example to mark a point or take a survey measurement, use the Peak bargraph to pinpoint the Peak position.
When using Null arrows:
Use the arrow heads to place the locator above the NULL point. If the Peak response is not at a maximum then this is evidence of a distorted field. If the Peak response is at its maximum level where the Null point is located then there is no or very limited distortion present.
In Peak+ mode the following indicators are displayed by the LCD:
- Right and left arrows
- Signal strength
To select Peak+ mode:
- Press the key until the Peak+ mode icon is displayed on the LCD.
Guidance mode offers good performance in distorted fields and provides three indicators to guide the user towards the target line.
The Left and Right Proportional Arrows become shorter as the locator approaches the target, and the Target Position Needle will move towards its central position. The Signal Strength reading will also reach its maximum value when the locator is positioned above the target.
Any deviation from all three indicators showing the target position in the same location could signal the presence of a distorted field.
In Guidance mode the following indicators are displayed:
- Proportional left and right arrows
- Target Position Needle
- Signal strength
To select Guidance mode:
Press the key until the Guidance mode icon is displayed on the LCD.
Null mode is used to verify a locate signal in environments with limited or no interference or distortion. Null mode gives a null response when it is directly over the line.
In Null mode the following indicators are displayed by the LCD:
- Signal strength.
- Right and left arrows.
To select null mode:
1 Press the key until the null mode icon is displayed on the LCD.
The sharp, null response can be easier to use than the Peak response but is vulnerable to interference and should not be used for locating, except in areas where there is no interference present.
Guidance Mode offers improved performance in such conditions while Peak+ mode can combine the Peak bargraph with Guidance arrows to combine fast and accurate locate tools.