Cables can be damaged during or after installation. Typically the damaged section is hidden from view behind walls, above ceilings, or buried underground. That's where the economical 612-12K comes in.
The ST612 Cable Fault Locator TDR (Time Domain Reflectometer) is affordable and easy-to-use equipment for metallic cables. ST612 can measure fault locations, such as broken lines, cross-connection faults, earth leaks, poor insulation and poor contacts up to 8 km distance.
When being used, the ST612 sends a short pulse to the line. The pulse will reflect back from fault spots and from the cable end in their typical manner. On the basis of the time of each reflection, ST612 can display the distance of the faults. Measurement resolution is 1 meter and dead zone 0 meters. One can choose either automatic testing, in which ST612 chooses test parameters itself, or manual testing, in which users can choose test parameters. ST612 has a clear LCD display, which shows test results graphically. A movable cursor helps to define fault distances.
Features:
Digital gain Adjustment control to make the gain adjustment very easy
Digital waveform automatically Identify technique to make sure no test dead zone
Top grade ARM single chip microcomputer can make calculations and judge the fault waveform exactly
Large colorful LCD display; humanized operation interface; six function keys can do all the tests
High-energy Li battery, continuous work 10 hours (with special charger)
Specifications:
Max range: 13154F
Highest resolution: 3.28F
Dead Zone: 0 m
Power consumption: 1W
Weight(kg): 0.42kg
Dimension(mm): 200 X 90 X 43mm
Working temperature: -15C~+45°CD
Storage temperature: -20°C~+55°C 8) USB storage (optional): transmit wave form to U disk, and
analyze the wave form on computer
Testing Principles:
Pulse testing is a kind of remote testing method; one can locate the fault point without testing on the field or testing with end-to-end coordination. The principle of the theory is: The instrument emits a pulse to the line, when the line has faults, the pulse reflection will change. If the come and back time can be measured, the location of the fault point can be detected.
Suppose the pulse transmission velocity in electric cable velocity is V, the come and back time that the pulse travels between the test point and the fault point is T, the fault distance is L, then: 2L = VT
. L = V T/2F
or example, the sending end transmits a pulse to the cable, after 20 us, the sending end get the reflection pulse. If the pulse transmission velocity in the electric cable is 700F/H s, the fault distance Lis
L = 700 X 20/2 = 7000F
Steps of Locating Fault Point: Diagnosis of fault characters; To insure the accuracy of the testing of fault point, the testing personnel shall diagnose the fault characters correctly and then choose the most suitable testing mode. The characters of telecom cable faults can be simply divided into the following several kinds:
Broken line One or many cable core line are broken
Crossed line The insulating resistance between the different couple of lines drops and causes the communication amplitude drops
Earthing fault The insulating resistance between the core line to the lead cover drops and causes low communication quality
Crosstalk noise When the cable core insulation material is invaded by water or humidity, the insulating resistance will drop and cause low communication quality or even blocks
Bad insulation The insulating resistance between different couple of lines and the core drops to a very low level, the communication quality comes under serious influences
Fault Testing: Cut off the cable to be tested on both sides lines or equipment. Make sure the cable to be tested is free of voltage. Using this instrument to do intelligence testing first, if the fault cannot be detected and then you can change to manual testing.
Locating Fault Point: The tester will Judge the approximate location based on the testing result, then check the cable, cable gland, cross boxes, etc., depending on the actual situation.
Intelligent Auto Testing:
Press "ON", connect the testing lead line and fault cable line. Press "AUTO" and then the instrument will show the testing result
Note: The default setting wave velocity is 200m/ us, when you perform intelligence testing, the user shall check whether need to adjust the velocity (see "Adjust wave velocity in the next section)
Value for Common Cable Wave Velocity (Insulators/Signal propagation velocity (m/us):
High Polymer: 0.56-0.62
Filled polythene: 0.64
Polythene: 0.67
Teflon: 0.71
Paper pulp: 0.72
Foamed polyethylene: 0.82
Paper: 0.88
9.5mm coaxial(w): 0.95
9.5mm coaxial(s): 0.98
Charge:
Current battery power is showed at the top-right of the screen. If the battery power is inadequate, please use the instrument charger to charge it
The indicator light of the charging adapter will be red when charging, and it will turn green after it's fully charged
Other Notes:
Keep display screen away from direct sunlight. The contrast ratio of LCD will drop when temperature higher than 60°C and it will return to normal when temperature is lower than 60°C
Before testing, better measure the voltage of fault cable to be tested, in order to avoid test errors or damage the instrument
Do not hit LCD screen