• Megger

Megger® Model DLRO10X

Digital Low-Resistance Ohmmeter



  • Accurate results in under three seconds
  • 0.2% basic accuracy
  • Auto current reversal cancels standing emfs
  • Fuse protected to 600 V
  • NiMH battery reduces weight
  • 250 mW power limit (with optional override) to avoid heating the test sample
  • Automatically detects continuity in potential & current connections
  • Visible warning of high voltages at terminals

Visible warning of current in test sample

Multiple operating modes including fully automatic

Alpha-numeric keypad for test notes

User-settable high and low limits

Auto-ranging with Manual option

Printer output and memory

Small, lightweight and portable — can be used in tight places, reduces the need for extra long leads and twoperson operation.

Four-terminal resistance method shows the true resistance of the item under test.

Bright LED (DLRO10) and LCD (DLRO10X) displays are easily visible under all lighting conditions and reduces human error.

Automatically applies forward and reverse currents which cancels out any standing voltages across the sample under test.

Checks for undue noise during measurement reducing the possibility of recording the incorrect result.

Automatically detects continuity in P and C circuits, preventing erroneously high readings to be taken due to high resistance contact.

Battery module features smart charging circuit, reducing accidental damage and cost.

Battery module has a battery condition indicator allowing the user to check the state of spare batteries without connecting to the instrument.

RS232 connector on the DLRO10X allows downloading of results in real time or stored for later retrieval.


The Megger® Ducter® DLRO10X brings new standards to low resistance measurement. They are fully automatic instruments, selecting the most suitable test current, up to 10 A dc to measure resistance from 0.1 µohms to 2000 ohms on one of seven ranges.

For users who desire more control over the measurement process, DLRO 10X uses a menu system controlled by a two-axis paddle to allow manual selection of the test current.

The DLRO10X also adds real-time download of results and on-board storage for later download to a PC.

The instruments are built into a strong, lightweight case that is equally at home in the field or in the laboratory. Light enough to be worn around the neck, they are small enough to be taken into areas which were previously too small to access.

Normally, measurements are made with forward and reverse currents to cancel the effects of any standing voltages across the test sample. The average value is then displayed within three seconds, to a basic accuracy of 0.2 percent.

The DLRO10X displays both forward and reverse measurements as well as the average of the two. DLRO 10X allows the user to set high and low pass limits, thereby enabling simple go-no-go testing.

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To assist operator safety and ease of use, both instruments are supplied complete with a pair of duplex handspikes with 4-ft (1.2 m) leads. One of the probes is fitted with LEDs which duplicate indicators on the instrument display indicating that all four contacts have been made, the presence of a high voltage across the load, and the presence of current flow while a load is discharging. If high and low limits are enabled on the DLRO10X, these lights will also show pass or fail.

A full range of test leads is available with probes, clamps and Kelvin clips. Power is provided by a Nickel Metal Hydride (NiMH) battery. These packs are interchangeable so that an exhausted battery may be recharged using the external charger supplied while testing continues using a spare pack. Standard charging allows the battery to be 90 percent charged within 2-1/2 hours from a 12 volt battery or from a standard 120/230 V ac supply via the supplied charger. The battery pack contains its own battery state indicator, which allows the charge-state to be monitored, even without being connected to the instrument.

The DLRO10X is fitted with RS232 communications that will allow results to be downloaded in real time or stored for later retrieval. Results may be stored within the DLRO10X complete with notes containing up to 200 characters which may be added using the on board keypad. These results can also be downloaded to a PC.



DC resistance measurements for these and others:

  • Switch and contact breaker resistance
  • Busbar and cable joints
  • Aircraft frame bonds and static control circuits
  • Integrity of welded joints
  • Intercell strap connections on battery systems up to 600 V peak
  • Quality control of resistive components
  • Small transformer and motor winding resistance
  • Rail and pipe bonds
  • Metal alloys welds and fuse resistance
  • Graphite electrodes and other composites
  • Wire and cable resistance
  • Transmitter aerial and lightning conductor bonding

Measurement Modes:

  • Measurement Modes A variety of measurement modes are available. Normal, Auto, Continuous and High Power are available on both the DLRO10 and the DLRO 10X.
  • Normal mode initiates a test by pressing the Test button on the instrument’s front panel after connecting the test leads. Continuity of all four connections is checked, forward and reverse currents are applied.
  • Auto mode allows forward and reverse current measurements to be made and the average displayed simply by making contact with all four probes. This mode is ideal when working with the supplied handspikes. Each time the probes are removed and reconnected to the load another test will be performed without the need to press the test button on the instrument.
  • Continuous mode allows repeated measurements to be made on the same sample. Simply connect the test leads and press the test button. The measurement is updated every 3 seconds until the circuit is broken.
  • High Power mode overrides the 250 milliwatt power limit thereby allowing higher voltages to be applied to the load. As this feature is usually applicable to small inductive loads, the measurement takes longer as the current needs to stabilize before a measurement can be taken.
  • Unidirectional mode, on DLRO10X only, applies a current in one direction only. This does not enable any standing emfs to be negated but speeds up the measurement process. DLRO10 will display the average of the measurements achieved using forward and reverse current, while DLRO10X displays both individual measurements and the average.

  • Literature
  • Specifications
pdf icon Description
++ DLRO10X Specification sheet (1.6 MB)
Full Scale Resolution Accuracy Volts (full scale) Test Current
1.9999 mΩ 0.1 μΩ ± 0.2% ± 0.2 μΩ 20 mV 10 A
19.999 mΩ 1 μΩ ± 0.2% ± 2 μΩ 20 mV 1 A
199.99 mΩ 10 μΩ ± 0.2% 20 μΩ 20 mV 100 mA
1.9999 Ω 100 μΩ ± 0.2% 0.2 mΩ 20 mV 10 mA
19.999 Ω 1 mΩ ± 0.2% ± 2 mΩ 20 mV 1 mA
199.99 Ω 10 mΩ ± 0.2% 20 mΩ 20 mV 100 μA
1999.9 Ω 100 mΩ ± 0.2% ± 0.2 Ω 200 mV 100 μA
Mode Manual, Auto, Continuous, High Power, Unidirectional
Control Fully automatic/manual
Speed <3 s for forward and reverse current and to display average
Measurement 4-1/2 digit seven segment LED
Range and Safety
LED indication
Real time or batch download via RS232
Storage Capacity
700 tests
Memo Field
Up to 200 characters per test. Input by onboardkeypad
Test Current
Test current < 10 mA: better than 10 ppm per secondTest current > 10 mA: better than 100 ppm per second
Voltmeter InputImpedance
Greater than 200 kΩ
Hum Rejection
Less than 1% + 20 digits additional error with 100 mV rms 50/60 Hz on potential leads.
If this level is exceeded, a warning will illuminate on the front panel.
7 Ah NiMH rechargeable battery supplied with instrument
Typically 1000 x 10 A tests
External 115/230 V 50/60 Hz charger (supplied) or from 12 V car battery
Charging Rate Standard
2-1/2 hours to 90% capacity at 68o F (20o C)
41o to 113° F (+5° to +45° C) at full specification14o to 122° F (-10° to +50° C) at reduced accuracy
-4° to 158° F (-20° to +70° C)
68° F (20° C)
<0.006% per °F over range 41o to 104° F(<0.01% per °C over range 5° to 40° C)
Slow charge
32° F to 113° F (0° C to +45° C)
Standard charge
50° to 113° F (+10° to +45° C)
Humidity (max)
90% RH @ 104° F (40° C) non-condensing
Altitude (max)
6562 ft (2000 m) to full safety specifications
In accordance with EN61010-1 600 V Category III
Meets EN50081-1 and EN50082-1 (1992)
8.6 x 4 x 9.5 in. (220 x 100 x 237 mm)
5.7 lb (2.6 kg) including battery module