Vivax Metrotech vLocML2, Руководство пользователя

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9 Using the vLocPro2
Page 50 of 72
9.1.3 Sonde Location
This is used for locating a Sonde only. A Sonde is a transmitting coil and the signal radiates in a different
manner than that of a line (see diagram b).
Due to this construction, the Sonde gives a different “Peak” pattern (see diagram b) – note that there are 3
distinct peaks – a small peak – a large peak – a small peak. The Sonde is located under the center of the
“large peak”, when locating across the direction of the Sonde it provides the conventional peak response.
Note also that the Compass Line Indicator points across the line of the Sonde when the receiver is directly
over it and the color of the compass change from clear to blue.
A Sonde is typically used for locating non metallic pipes or ducts, and the camera end of a sewer inspection
camera. Low frequency versions (512Hz/640Hz) can transmit through some metallic pipes such as cast iron
pipes – which is why they are frequently used with sewer inspection cameras.
The procedure for Depth Measurement is the same as in line location, but must be done in the Sonde mode.
Depth measurements taken from a Sonde in any mode other than Sonde mode will be inaccurate.
9.1.4 Using the Compass Feature to Locate Sondes
Switch on the vLocCam. Select the frequency to match the Sonde frequency. Use the mode pushbutton to
select Sonde.
Stand in the approximate vicinity of the Sonde. Press the “+” pushbutton to increase the gain so that a steady
bar graph reading is displayed. If no or very fluctuating bar graph is shown, it means that the Sonde is not in
the expected vicinity. If this is the case pull back the Sonde to a known position, which may be the point the
Sonde enters the pipe, and start the search here.
Rotate the locator until the compass is pointing at 12 o’clock. Walk in the direction of the compass keeping
the compass pointing at 12 o’clock. The locator will lead you in an arc that crosses over the Sonde. Press the
gain pushbuttons to keep the bar graph on scale. The maximum bar graph indicates the position of the Sonde.
(a) (b)