Smart TDR Cable Fault Locator with 0.1m Minimum Resolution

Product characteristics

• Time Domain Reflectometry (TDR) technology
• Precise cable fault location
• Distance testing capability
• 0.1m minimum resolution
• Smart diagnostic functionality

Working principle

Cable fault tester adopts traveling wave method test principle:

1. Traveling wave method: When the radio wave is transmitted in the transmission line, if the transmission line is not uniform, that is, the characteristic impedance of a point in the transmission line changes, when the radio wave is transmitted to the point, in addition to continuing to transmit to the load, it will also produce reverse transmission and return to the test end, we call the reverse transmission of the wave reflected wave, the phenomenon of the wave producing reverse transmission is called the reflection phenomenon of the wave. The so-called traveling wave refers to the general name of incident wave and reflected wave.

2, when the radio wave is transmitted in the transmission line, the polarity of the echo at the short circuit point is opposite to the polarity of the emitted pulse, and the polarity of the echo at the break point (including the cable terminal) is the same as the polarity of the emitted pulse. Using the pulse method, the instrument can easily determine the distance between the fault point and the test end according to the polarity of the echo.

3. The cable fault tester applies a low-voltage pulse signal to the cable under test, and the pulse signal generates a reflected signal through the fault point of the cable. The cable fault tester processes the reflected signal and presents a waveform diagram. The coarse fault distance of the cable under test is determined by analyzing the reflected waveform.

The wiring method is as follows: Use a single Q line to connect the "sampling interface" of the cable fault tester to the faulty phase line and cable shielding layer. The low voltage pulse wiring is shown in the figure below.

Note: During the test, it must be confirmed that there is no electricity stored in the cable body.

Step 1: Clamp the signal line to test phase A. The test phase selection of the corresponding interface is also set to phase A. Then click the sample/keep button on the interface to enter the sampling state. Observe the sampling waveform. If you think the sampling waveform is good, click the sample/keep button to enter the hold state for waveform analysis. Refer to "Waveform" Example -Analyze waveforms.

Step 2: Clamp the signal line to test phase B. Repeat the first step of the testing process.

Step 3: Clamp the signal line to test phase C. Repeat the first step of the testing process.

After the above three-step test is completed, the interface displays the pulse test waveforms of the three-phase cable at the same time.