• Megger

Megger ® BTDR1500

Combined Automatic Resistance Bridge & TDR Fault Locator


  • 10 m to 3 Km TDR Measurement Ranges
  • Automatic Resistance Bridge
  • Measurement range up to 100 Km
  • Built in Insulation tester
  • DC Volt & Loop Resistance Meter
  • Dust & Shower Proof to IP54



Suitable for Telecom, Coax, Datacom & Power Cables


TX Null Balancing circuit allows the transmitted pulse to be eliminated from the displayed trace, removing the “Dead Zone” and allowing faults to be identified at the near end of the cable. Pulse widths down to 7 ns allow for accurate discrimination between faults. Pulse widths up to 3000 ns and four gain settings allow for the detection of cable faults up to 3 km away. Auto range facility selects most appropriate measurement range according to cursor position to ensure ultimate accuracy in fault location.

Automatic Resistance Bridge

Advanced automatic balance Resistance Bridge enables location of cable faults up to 100 km away to an accuracy of 0.2%. Two or three wire operation enables accurate fault location on balance or unbalanced cable pairs. Loop resistance measurement up to 2 k½ enable cable losses and line length to be calculated to ensure suitability of lines for use in Digital Transmissions. Insulation resistance measurement range enables identification of the nature of a cable fault and assists in the pre-qualification of potential DSL lines. DC Voltage measurement indicates the presence of Telecom Network Voltages (Battery Voltage)


The Megger® BTDR1500 is an advanced instrument capable of identifying nearly all types of cable fault using both Time Domain Reflectometry and Automatic Resistance Bridge Techniques. It offers exceptional features and a range capability normally associated with larger, more expensive products. Location of open circuits and low resistance faults using the TDR facility can be performed from 0,1 m to 3000 m with a measurement accuracy of 1%. Location of faults using the Automatic Resistance Bridge facility can be performed on cables up to 100 km in length (dependent on conductor diameter and resistance) with a measurement accuracy of 0,2%.

In TDR mode the BTDR1500 can be used on any cable consisting of at least 2 insulated metallic elements, one of which may be armouring or the cable screen. The instrument can be carefully matched to the cable using the Tx Null control allowing long lengths of cable to be easily tested and elimination of “dead zone” such that faults close to the instrument can also be seen. The propagation velocity value can be similarly adjusted to match the cable, thus ensuring an accurate distance measurement can be directly read. To enable a wider range of faults to be detected in TDR mode, the gain of the instrument is also variable, allowing more minor faults to be identified over the entire length of the cable.

The Automatic Digital Bridge can measure the insulation resistance up to 200 M½ (insulation test), the loop resistance up to 2 kohm(2-wire loop test) and the series leg resistance of up to 1 kohm (3-wire loop test). Where a fault causes the insulation resistances to lie below 20 Mohm, the fault position can be determined (AUTO test) relative to the meter end and also relative to the far end where a loop has been made by fitting a strap between the wire under test and one or two return wires. In the case of a single return wire (2-wire test method), the position of the strap is assumed to be at the position of half the total loop resistance. If two return wires can be used (3-wire test method) the position of the strap will be known to greater accuracy and will be independent of the resistance of either of the return wires.

In addition to the TDR facility and Automatic Resistance Bridge, the BTDR1500 has a voltmeter range for measuring a DC voltage to ±250 V and can verify if a telecomm cable has a Telecom Network Voltage (TNV) present on it.

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Suitable for the first step in pre-qualifying DSL and other digital lines by identifying high resistance faults that would otherwise cause signal attenuation within the cable. Excessive signal attenuation will reduce DSL available transmission distances and the associated reduction in signal amplitude will increase error rates and ultimately reduce transmission speeds. Also measures loop resistance to enable losses and line length to be calculated to ensure suitability of lines for use in Digital Transmissions.

  • Literature
  • Specifications
pdf icon Description
++ BTDR1500 Specification sheet (1.6 MB)
Ranges: 10 m, 30 m, 100 m, 300 m, 1 km, 3 km
Accuracy: ±1% of range± pixel at 0,67 VF
Resolution: 1% of range
TX Null: 0 Ω to 120 Ω
Output impedance: 100 Ω
Velocity Factor: Variable from 0,30 to 0,99 in steps of 0,01
Gain: Set for each range with four user selectable steps
Refresh Rate:
Once per second for 5 minutes after last key press

Stays on for 1 minute when activated

Display: 128 x 64 pixel Graphics LCD
Bridge Specifications
Loop Resistance ranges: 0 to 190 Ω in steps of 0,1 Ω190 Ω to 2000 Ω in steps of 1 Ω
Fault Resistance Ranges:
±0,2% ±1 digit from0 Ω to 1 MΩ ±0,2% ±3 digits from 1 MΩ to 5 MΩ ±0,2% ±6 digits from 5 MΩ to 10 MΩ
Loop reading:
±0,2% of reading ±1 digit on ½
Voltage to Line:
100 V d.c. nominal
Current to Line:
100 mA d.c. nominal
Insulation range:
0 to 19 MΩ in steps of0,01 MΩ 19 MΩ to 200 MΩ in steps of 0,1 MΩ
Insulation Accuracy:
±0,2% of reading ±1 digit
General Specifications
Input protection:
300 V d.c. or 300 V a.c. 60 Hz (min source Impedance>1,5 ½)
Power down:
Automatic after 5 minutes inactivity
Back light:
1 minute when activated
128 x 64 pixel Graphic LCD