Using Accessories

Follow Avatar Anthony Caplin
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In this article

About accessories

Both the transmitter and locator are compatible with a wide range of accessories.

When an accessory is connected, the locator or transmitter will recognize it and will enable the mode appropriate to the accessory. For example, attaching an A-Frame to the RD8200 locator will automatically switch the locator to fault-find mode and limit the number of available frequencies to those that are compatible with the A-Frame. The LCD will also display an icon of the accessory and will remove any non­essential icons from the screen.

Radiodetection supply an accessory sheet with pictures and details of all applicable accessories which is available at:



Radiodetection supplies an optional headphone set for the RD8200 locator. The headphones feature an adjustable headband to ensure a tight fit when used in the field. The accessory headphones also feature volume adjustment for both left and right speakers.

Connect the 3.5mm headphone jack into the locator’s headphone socket, which is located next to the accessory panel.

warning icon.pngWARNING! Before wearing headphones, lower the locator’s volume levels to help prevent damage to your hearing.

warning icon.pngWARNING! Wearing headphones may impede your awareness to dangers in the field such as moving traffic or other heavy machinery. Exercise caution!


Locator clamps

A locator clamp is used to positively locate and identify a cable when several cables are running close together.

A target cable can be identified in a chamber, on a tray or other access point by fitting a clamp to the locator and examining each cable in turn. Signal strength response shown on the locator display should be noted for each cable.

When to use clamps

Clamps can be used where:

  • Several cables or pipes run in close proximity to each other.
  • A cable or pipe is accessible at an inspection hole or manhole.

NOTE: The standard clamp cannot be used with CD. A special CM / CD clamp is available to clamp the lower frequency CD signals.

Connecting a clamp

  1. Put the clamp connector into the accessory socket on the front of the RD8200 locator.
  2. Place the clamp around the pipe or cable and switch the locator on.
  3. Set the frequency to the same as that on the transmitter.
  4. Put the clamp around each cable in turn and note the bar graph response. Compare the strength of response from each cable. The cable with a substantially stronger response than the others will be the cable to which the transmitter signal has been applied.



Connecting clamps

To ensure that the target cable has been correctly identified, reverse the positions of the transmitter and locator and check that the strongest response is still received from the target cable by the locator in its new position.


Locator clamp range

Standard clamps

The clamp plugs into the locator accessory socket and is used for cable identification at points where the cable can be accessed. The standard clamps are suitable for cables up to 130mm (5¼”) diameter.



Standard Clamp


Small clamp

The small clamp performs the same function as the standard clamp but is useful in cramped situations where there is insufficient access for the standard clamp.

The small clamp is suitable for cables up to 50mm (2”) diameter.


Current Direction™ (CD) and Current Measurement (CM) clamp

Locator CD / CM Clamp


This accessory is used to identify a particular cable that is bunched with several other cables or in close proximity to other cables. The combination of direction current and current magnitude is extremely useful for identification purposes.


Transmitter clamps

The transmitter clamp fits around a pipe or cable and safely applies a signal to a live insulated cable without interrupting or disconnecting the supply. The clamp applies a very discriminating signal to a target line with reduced coupling to other lines. A clamp can sometimes be a more effective method of applying the signal than Direct Connection.

The target line will carry the strongest signal. The other lines will carry the weaker return signal. If the system comprises only two conductors, they may carry equal signals.

warning icon.pngWARNING! Do not clamp around uninsulated live conductors

warning icon.png WARNING! Before applying or removing the clamp around a power cable, ensure that the clamp is connected to the transmitter at all times.

The clamp may buzz or vibrate if it is placed around a power cable that has significant net current flow. This is normal and does not harm the equipment.


Connecting the clamp



Transmitter output socket

Connecting transmitter clamps

  1. Plug the clamp into the transmitter output socket.
  2. Put the clamp around the pipe or cable and ensure that the jaws are closed. Switch the transmitter on.

Clamp connected icon

The line should be grounded (earthed) on each side of the clamp for the signal to transfer to the line. Ground the line if necessary. An insulated cable may be traced even if it has no actual ground connection, providing a reasonable length is buried either side of the clamp to provide capacitive coupling to ground (earth).

NOTE: It is not necessary to make a ground connection from the transmitter when using the clamp.


Transmitter clamp range

Although transmitter and locator clamps look the same, they have different internal windings. To prevent the wrong clamp being connected, transmitters and locator clamps have plugs of a different orientation.

Standard signal clamps

The standard clamps apply the transmitter signal very selectively and effectively to a target cable up to 130mm (5¼”) in diameter using frequencies from 8kHz to 200kHz.

The standard and small clamps have a double spring action for positive toroidal contact.

Small signal clamp

The small signal clamp is useful for applying signals from 8kHz to 200kHz to a target cable in a pedestal or other place with limited space. The clamp is suitable for cables up to 50mm diameter.

Current Direction (CD) clamp


cd clamp.png

Transmitter CD clamp

The CD clamp plugged into the accessory socket of the transmitter enables CD signals to be applied to individual cables.

warning icon.pngWARNING! The transmitter must only be connected to live services using the appropriate accessory such as a plug connector or live cable connector.


Transmitter external power supply

The external Mains or vehicle power supplies provides an alternative and convenient method of powering the transmitter.

warning icon.pngWARNING! The mains power supply rating are: 100-240VAC, 1.3A. Always use an adequately rated detachable mains lead.

warning icon.png WARNING! The mains power supply is not IP rated and should not be used in wet locations



Transmitter DC Input

To use the mains or vehicle power supply units connect them to the DC input socket in the transmitter before connecting them to the mains or vehicle supply socket.

warning icon.pngWARNING! The mains PSU supply cable is the disconnecting method for isolating the unit from the main supply.

warning icon.png WARNING! The battery compartment lid is the disconnecting method for isolating the unit from the battery supply.

warning icon.pngWARNING! Do not position the equipment so it is difficult to disconnect the unit from each supply.

warning icon.png WARNING! Protection will be impaired if used in a manner not specified.



Sonde overview

Choosing a suitable sonde

Radiodetection offers a wide range of sonde to suit most applications: From the ¼” / 6 mm diameter S6 33kHz microsonde which, with a range of 6.6” / 2m, targets fiber-optic micro ducting or other small non-conductive pipes, to the 33kHz Super Sonde, which with a depth range of 50 feet / 15m targets deep sewer pipes.

Consult the precision locate accessory range brochure or web page on for a full list of all available sondes and their technical specifications.

Check that the sonde has sufficient range for the application and is dimensionally small enough and sufficiently robust for the application. Ensure that the frequency of the sonde corresponds with the locator frequency; the locator will not locate the sonde unless the frequencies are the same. Sondes are marked with their transmitting frequency. Ensure that the means of propelling the sonde is available together with the correct fittings and couplings.


Insert a new battery into the sonde. A new battery or a freshly recharged battery should be used at the beginning of each day and preferably at the start of each new job.

Before inserting the sonde, check that the sonde and locator are at the same frequency and working correctly. To do this, place the sonde on the ground at a distance from the locator that is equal to the rated depth of the sonde. Point the locator at the sonde with the antenna in line with the sonde (the opposite of using the locator to locate a line) and check that the bargraph reading exceeds 50% at maximum sensitivity.

Propelling a sonde

Sondes have a thread at one end for connecting to drain rods, or to other devices for inserting and propelling the sonde along a drain or duct. Sondes may be floated along drains at the end of a tether and floats are available for fitting to the sewer sonde and super sonde. Sondes can be strapped to high-pressure water jets or similar devices used for cleaning, maintaining and inspecting drains. Sondes used in underground drilling and boring operations are normally housed in the boring or drill head behind the boring or drill bit.

Locating and tracing a sonde

The sonde radiates a Peak field from the center of its axis with a ghost signal at each end of the Peak. Move the locator a little way behind and then in front of the axis of the sonde to detect the ghost signals. Finding the two ghost signals positively confirms the locate. Reduce the locator sensitivity to lose the ghost signals but still indicate a clear Peak response directly over the sonde. Locator sensitivity is now set for tracing the duct or drain unless the distance between sonde and locator changes.

Propel the sonde three paces along the drain or duct and stop. Place the locator over the supposed position of the sonde. Do not adjust the sensitivity level.



Sonde deployment


To locate a sonde:


Locating a sonde


  1. Move the locator backwards and forwards and stop when the bar graph indicates a Peak. You can use the LCD compass to orient the blade of the locator with the direction of the sonde.
  2. Rotate the locator as if the blade is a pivot. Stop when the bar graph indicates a Peak. 
  3. Move the locator from side to side until the bar graph indicates a Peak. 
  4. Repeat 1, 2 and 3 with the antenna vertical and resting on or just above the ground. The locator should then be directly above the sonde with the antenna in line with it. Mark the position of the sonde and its direction. 
  5. Propel the sonde a further 1 or 2 meters, pinpoint, and mark the position. Repeat this pinpoint procedure at similar intervals along the line of the drain or duct until the survey is completed.


Checking sonde depth

The RD8200 locator will automatically display the depth of a located sonde providing the locator is correctly oriented and positioned above the sonde. Using the LCD compass as a guide, rotate the locator until the compass indicates the sonde is in East / West position.


Calculating sonde depth

Calculation method

Pinpoint the sonde. Move the locator in front of the sonde and still with the antenna in line with it, increase sensitivity to find the Peak of the ghost signal. Move the locator to behind the sonde ensuring that the locator blade is always in line with the sonde. Find the null positions A and B. Measure the distance between them and multiply by 0.7 to give an approximate depth measurement.



The Flexitrace is a traceable plastic covered fiberglass rod incorporating wire conductors and is used for locating small diameter, non-metallic pipes to a depth of 3 meters. The Flexitrace can be inserted into a pipe or duct as small as 9 mm / 3/8” internal diameter, and with a minimum bend radius of 250mm. Batteries are not required, as the FlexiTrace is powered by any Radiodetection transmitter.

The FlexiTrace has a maximum power rating of 1W. When using the FlexiTrace with a Radiodetection Tx-5 or Tx-10 transmitter the output limit must be set to 1W in the MAX P menu and the output voltage limit set to LOW in the MAX V menu.

warning icon.png WARNING! Failure to follow the Tx-5 or Tx-10 instructions above may result in the tip of the FlexiTrace becoming too hot to touch, resulting in risk of personal injury and damage to the equipment.

The FlexiTrace can be used in two modes: Sonde mode or Line mode. In sonde mode only the tip of the FlexiTrace is energized whilst in line mode its whole length is energized.

To use as a sonde, connect both transmitter leads to the FlexiTrace stud terminals. As the FlexiTrace terminals are not color coded it does not matter to which terminals the leads are connected. To use the FlexiTrace in line mode, connect the red transmitter lead to one of the FlexiTrace terminals and connect the black transmitter lead to a suitable ground connection







When to use a stethoscope

At times, it may not be possible to put a clamp around a cable because of congestion or because of inaccessibility. A stethoscope antenna should be used in place of a clamp to identify the target cable(s).

How to use a stethoscope

Plug the stethoscope into the locator accessory socket. Press the concave head against each cable in turn to detect a maximum signal.

Stethoscope range

Large stethoscope antenna

The large stethoscope antenna, which plugs into the locator accessory socket, is used for cable identification in situations where the cable is exposed. It is particularly useful for identifying heavy cables lying in a tray where it is not possible to fit a clamp. The concave detector head on the end of the insulated, flexible gooseneck is placed firmly against the cable to be identified. If there are a number of cables, the stethoscope antenna will give the strongest response from the cable to which the transmitter signal has been applied.

Small stethoscope antenna

The small stethoscope antenna has a 25mm (2”) concave head at the end of a 2m (6½ ft) lead. The small stethoscope can be screwed into an extension rod or used at the end of several extension rods joined together for identifying inaccessible small cables.

Miniature hi-gain stethoscope

The miniature stethoscope is similar to the small stethoscope but has no handle or facility for extension rods.

The miniature stethoscope can also be used as a miniature antenna for locations where the bulk of the locator makes it inconvenient for use, such as locating pipes or cables in walls.

CD stethoscope

In restricted areas, the CD stethoscope can be used to obtain current direction but not current measurement.


Submersible antenna

When to use a submersible antenna

Tracing buried pipes and cables across waterways and estuaries are frequent and critical locating applications. Less frequent but equally important is tracing and locating lines between the mainland and offshore islands. When locating pipes and cables the locator sensing antennas should be as close as possible to the target line so it is not practical to locate lines buried under a river or seabed from the surface. In most cases, it is necessary to measure the depth of cover to ensure the line is protected from dragging anchors or other underwater hazards.

The submersible, double depth antenna is suitable for use under water for tracing pipes or cables. There is a weight at the bottom of the antenna for stability and the unit has been pressure tested to IP68 to a depth of 100m (300ft).

The antenna is supplied with 10m of submersible marine umbilical cable as standard, but lengths of up to 100m can be supplied. The extra length enables the antenna to be carried by a diver on a riverbed or seabed while the locator is used in a surface vessel. It is crucial to have effective communication between the operator with the locator and the diver with the antenna.

Alternatively the antenna can be fastened to the end of a non-metallic boom from a barge and lowered to the riverbed or seabed.

How to use a submersible antenna

Apply the transmitter signal to the target line at an access point on the shore. The submersible antenna line for tracing the line underwater is plugged into the accessory socket of the locator. The locator is used onboard a boat, which should by positioned directly over the line. The transmitting signal should be applied by Direct Connection with the strongest possible signal and at the frequency that the submersible antenna is calibrated to. Make a ground connection about 50m (160ft) from the transmitter. Test the quality of signal on the line before locating on the water.

NOTE: The submersible antenna is calibrated to work at one frequency.

Tips for using a submersible antenna:

The user in the boat should be a specialist or have considerable experience using a locator so that they can give concise instructions to the diver.

It is prudent for the pair to practice working together on dry land before attempting to locate underwater. Using the antenna the diver should locate and trace a known line blindfolded receiving directions from the user with the locator out of sight of the line and the diver.

Because of rapid signal loss and a combination of large surface area and very conductive soil there may be problems applying a suitable signal for tracing a large diameter pipe. It may be necessary to use a high power, low frequency tracing signal.

It is necessary to define a method of recording target line position and depth before starting work in the boat or on the seabed.



Using a submersible antenna

warning icon.pngWARNING! Only properly licensed and experienced divers should attempt to use the submersible antenna.


Phone/Tablet mount

When using a mobile device running a compatible application, such as RD Map for Android, you can use the Phone or Tablet mount to conveniently hold your device next to the locator and have immediate visual feedback on the survey measurement points you are marking.


mount bracket.pngphone tablet holder.png

Phone/tablet mount kit


To use the mobile device mount:

bracket positioning.png

Bracket positioning


1. Insert the mount bracket locating pins in the mounting holes at the back of the locator screen.

2. Secure the rubber o-ring around either of the 2 fixing studs and loop it around the locator handle. 

bracket secured.png

Bracket secured


3. Stretch the other end of the rubber o-ring over the remaining fixing stud. 

4. Use the hand tightening bolts to loosen up the arm brackets and to attach it over the bracket’s arm support ball.

5. Add the phone or tablet holder.

6. Tighten the hand tightening bolts to secure the mount.

7. Position the phone or tablet to the front of the locator. 

correct positioning.png

Phone/tablet correct position


warning icon.pngWARNING: Mobile phones or tablets may interfere with the locator’s performance if positioned not in front of the locator. 

Some mobile phone or tablets may affect the locator’s performance, even if used in the correct position. This may be obvious in situation where the locator is trying to detect a very small signal and it manifests itself by an unstable signal shown on the bargraph and/or depth or current measurement.

If in doubt remove the mobile phone or tablet to verify if these are affecting the behavior of the locator.

No cables, such as power leads or headphones, must be connected to the phone or tablet when used with the mount kit.