If you have any questions contact our manager 24/7:
DC current resistance measurement in inductive and noninductive circuits in the range from 10 µOhm ÷ 10 kOhm for the currents of up to 10А
Specific modes for measuring different objects
High precision of measurements both in laboratory environment and at substations
Automatic measurement data processing and nonvolatile memory
OLTC in-place check mode (DRM method)
High level of protection and safety conformance in regard to
Interactive control and communication with PC
Measuring cables of ergonomic design
Power from the mains and/or integrated storage battery

Milliohmmeter MIKO-8M new version

DC current resistance measurement in inductive and noninductive circuits in the range from 10 µOhm ÷ 10 kOhm for the currents of up to 10А
  • Windings of power and measurement transformers, windings of electric motors, generators, linear compensators and windings of other high-inductance equipment;
  • Contacts of circuit breakers, resistors, buses and other inductance-free circuits;
  • Selector contacts of OLTC devices,  of earthing devices, disconnecting switches and of other detachable and non-detachable contacts;

A new version of MIKO-8M with be delivered to the warehouse in the second quarter of 2018 (production of MIKO-8 was discontinued). Orders are accepted. Comparison of the first version of the device and its modification is at Reference..

Specific modes for measuring different objects

The device integrates special-purpose modes for measuring different objects with account of their specific features: resistive and inductance objects; voltage transformers; current and power transformers; generators, motors, compensators, connection filters, and magnets.

High precision of measurements both in laboratory environment and at substations

High precision of measurements both in laboratory environment and at substations under industrial noises is achieved owing to calculation and setting (for any resistance) of specific maximum possible test current limited by effective power of the device only. Therefore, ratio between a valid signal to winding resistance and the noise amplitude remains high at any resistance.

Automatic measurement data processing and nonvolatile memory

The archive of measurements available in the device allows review, copy or deletion of test results stored in the self-powered memory of the device (up to 1000 measurements), as well as for supporting the following computations:

  • Automatic calculation of relative deviation of winding resistance at three phases against each other;
  • Automatic recalculation of linear resistance of windings, connected with delta or star connection to the phase winding resistance;
  • Automatic recalculation of resistance at current temperature to the resistance at certified temperature (with due regard to winding material);
  • Automatic calculation of deviations measured and normalized to the certified temperature of winding resistance in relation to the certified values of resistances;
  • Automatic calculation of winding temperature based on its measured and certified value of resistance and certified temperature.
OLTC in-place check mode (DRM method)

РOLTC "in-place" check mode allows carrying out of in-place check and diagnostics of OLTC with current-limiting resistors without removing the contactor tank covers. This mode involves measuring of instantaneous current passing at first through the transformer cover and then through OLTC contracts at switching from one tap to another.

A graph of current variance at contacts switching is drawn up and the time of switching as well as the general technical condition of the instrument is checked on its basis. Analysis of the acquired graphs provides not only for sorting out of elements by fault-free/faulty criteria but also for defining the nature of the defect allowing eliminating of fault-free OLTCs opening.

Measurements in milliohmeter mode and in in-place check mode complement each other and provide a comprehensive picture of the state of transformer.

High level of protection and safety conformance in regard to
  • exceeding of measuring current;
  • electromotive force (emf) of self-induction.

At disconnection of the measuring cable from transformer bushings or from the instrument as well as at disconnection of the mains cable from the mains in the course of measurement, emf of self-induction of up to several kV is generated in the disconnected circuit and the electric arc appears in the break point.

MIKO-8М is characterized by the redundant protection against emf of self-induction in case of involuntary disconnection of the measuring cable or power cable protecting users from electric shock and the instrument from being damaged.

  • a set of required protective means against superheat of the measuring unit;
  • protection grounding contact in the mains plug and safety earthing terminal on the case of the measuring unit.
Interactive control and communication with PC

Color graphic display of high brightness ensures easy reading on a sunny day, whereas intuitively understandable interface with a sensor display facilitates the instrument use.

The Instrument can be manipulated either from the film keyboard or from the sensor display, as suits..

Personal computer connection through USB or Bluetooth allows for:

  • Controlling the instrument with the help of PC;
  • Systematizing and storing the results on computer;
  • Drawing up of measurement reports

Data transmission to the computer and filing of measurement results is performed with the help of a special program developed by the manufacturer.

Measuring cables of ergonomic design

Cables of different length and the grip of alligator type clamps allowing performance of ground measurement as well as the measurement from the cover of transformers of all voltage types.

Power from the mains and/or integrated storage battery

For customer’s choice the MIKO-8M milliohmmeter has two modifications: with an in-built battery (MIKO-8MA) and without an in-built battery (MIKO-8M). The device can also be powered from the mains (≃ 110÷220, 330V).

Specifications Value
Resistance range 10 µOhm ÷ 10 kOhm
Maximum permissible intrinsic error of resistance measurement ±(0.1% + 0.5 µOhm)
Best resolution 0.1 µOhm
Measuring current intensity, А 0.001 ÷ 10
Relative drift of measuring current intensity, %/s ±0.002
Amperage measurement range in the DRM mode, A 0.1 ÷ 10
Limits of allowable main and relative error of amperage measurement in the DRM mode ±1 %
Maximum consumed power, W 120
Maximum output capacity, W 60
Mains voltage: AC (valid value) 90 ÷ 253V
Mains voltage: DC 127 ÷ 354V
Period of charging a completely discharged battery, not to exceed 3 hrs
Type of data transmission channel USB, Bluetooth
IP rating in operating state IP40
IP for transportation IP64
Operating temperature range, ºС -20 ÷ +55
Maximum measuring unit weight with battery, kg (MIKO-8MA) 4.0
Maximum measuring unit weight without the battery, kg (MIKO-8M) 2.7
Dimensions, mm 270х250х130
Interface language English
User manuals language English
Calibration interval, year 3
Standard complete set
Photo Item, Index Application
MIKO-8 or MIKO-8MA<br>measuring unit MIKO-8 or MIKO-8MA
measuring unit
СКБ049.00.00.000
or СКБ049.00.00.000-01
The instrument and accompanying documents: calibration certificate, operation manual and record book.
Measuring cables <br><b>on order</b> Measuring cables
on order
As a matter of convenience for the user, measuring cables are not included in the standard complete set. Each user can select a cable to his/her own requirements. Select at least one measuring cable (see "additional complete set on order" below).
Mains cable Mains cable СКБ018.09.00.000 For connecting the instrument to the power line. Temperature range -25°С ÷ +120°С. Rubber insulation (length – 2 m).
Ground wire Ground wire СКБ010.01.00.000 For instrument case grounding. Equipped with a ground clamp and screw end cap. Rated current – 50А.
Zero resistance equivalent Zero resistance equivalent СКБ023.15.00.000 Resistance zero point accuracy check. Value – 0.000 µOhm.
Shunt 75ШСММ3 Shunt 75ШСММ3 Performance check. Value – 1 MOhm ± 0.5%.
VP2B-1V-2А cut-out (2 pcs.) VP2B-1V-2А cut-out (2 pcs.) For power source protection.
Cable USB 2.0 A-B Cable USB 2.0 A-B For connecting the instrument to the computer and its control from PC (length – 1.8 m).
Attachment devices set kit Attachment devices set kit СКБ126.06.02.000
Additional complete set (on order)
Photo Item, Index Application
Measuring cable Measuring cable СКБ041.18.00.000 The cable is made in the form of elastic silicone tube resistant to low and high temperatures and corrosive media. Alligator type clamps with the jaw of up to 80 mm. Length – 8.5 m
Measuring cable Measuring cable СКБ041.19.00.000 Cable for measuring the transient resistance of contacts; measurement of CT and VT windings resistance. Clamps: current and potential contacts: ‘crocodile’ clamps with 25mm jaws (2 pcs.), and removable probes with a 3mm diameter plug 70mm long (2 pcs.). Length: 3 m.
Measuring cable Measuring cable СКБ041.26.00.000 Cable for connection to transformer leads as an alternative to cables available СКБ041.18.00.000. The cable is made in the form of elastic silicone tube resistant to low and high temperatures and corrosive media. Clamp jaw of up to 103 mm. Length - 8.5 m.
Test cables for CT and VT Test cables for CT and VT СКБ041.21.00.000 For measuring the resistance of CT and VT windings of both in-built and stand-alone transformers / circuit-breakers. Alligator type clamps with the jaw of 25 mm. Length – 4 m.
Measuring cable extension Measuring cable extension СКБ031.20.00.000 Recommended for application together with measuring cables СКБ041.18.00.000 (throat of up to 80 mm) and СКБ041.26.00.000 (throat of up to 103 mm). The extension is made in the form of elastic silicone tube resistant to low and high temperatures and corrosive media. Length - 6.5 m.
Short-circuiting cable (set of 3 pcs.) Short-circuiting cable (set of 3 pcs.) СКБ035.31.00.000 For applying the DRM-test one of the short circuiting cable sets for closing secondary circuits shall be ordered.

This cable is for OLTC devices of auto transformers.

This set consists of thee short-circuiting wires 12m long each. Both ends of the wire are furnished with welded ‘crocodile’ with the jaw of up to 50 mm.
Short-circuiting cable (set of 3 pcs.) Short-circuiting cable (set of 3 pcs.) СКБ041.23.00.000 For applying the DRM-test one of the short circuiting cable sets for closing secondary circuits shall be ordered.

This cable is for OLTC devices of power transformers.

This set consists of thee short-circuiting wires 3m long each. Both ends of the wire are furnished with welded ‘crocodile’ clamps with 80 mm jaws.
Additional resistor Additional resistor СКБ032.25.00.000 For in-place OLTCs monitoring at apparent resistance of the winding of no more than 0.5 Ohm.
Reference inductor adaptor Reference inductor adaptor СКБ023.12.00.000 For verification laboratories: inspection / calibration of the instrument.
Cable and documentation bag Cable and documentation bag СКБ126.06.00.000 Handy, sturdy and wear-resistant bag for carrying cables, documents and other additional component parts to MIKO-8M or MIKO-8MA.
Manipulating rod Manipulating rod СКБ010.41.00.000
СКБ010.41.00.000-01
СКБ010.41.00.000-02
The rod is designed to ensure convenient connection to contacts of a transformer inputs.

The rod is completed with a clamp with current and potential contacts connected by wires with the measurement platform. Test cables are connected to the measurement platform from the ground.

  • Manipulating rod for equipment of up to 35kV (2.2 m);
  • Manipulating rod for equipment of up to 110kV (3.7 m);
  • Manipulating rod for equipment of up to 220kV (5.1 m);
Reviews (2)
Comparison of milliohmmeters produced by SKB EP
Comparison of milliohmmeters produced by SKB EP
SKB EP Company sells three types of instruments for measurement of DC electric resistance of windings of transformers, electric motors, electric magnets, cables and of other inductance and inductance-free circuits: the MIKO-7 with basic and updated software, the MIKO-8M and the MIKO-9.
Comparison of milliohmmeters MIKO-7 and MIKO-8 with the new modifications
Comparison of milliohmmeters MIKO-7 and MIKO-8 with the new modifications
The SKB EP Company moves forward and continuously updates its products that is evidenced by two new versions of milliohmmeters to be manufactured in 2018: MIKO-7M and MIKO-8M.