Milli-ohmmeter MIKO-8M(A) with integrated check of OLTCs

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Resistance measurement in inductive and non-inductive circuits in the range of 1 μΩ - 10 kΩ

Automatic setting and systematization of measurement results

High precision measurement modes

Various auto calculations and non-volatile memory

Non-demountable estimation of the OLTCs (DRM test)

High level of protection and safety conformity

Touch screen, remote control and bluetooth data transfer

Variable instrument configuration

Two modifications of the instrument with different types of power supply

Milli-ohmmeter MIKO-8M(A) with DRM mode review

Fastening the measuring cable of the MIKO-8M(A) milli-ohmmeter to the diagnostic object

An example of fastening a measuring cable SKB041.18.00.000 of a milli-ohmmeter of MIKO-8M(A)

MIKO-8M(A) milli-ohmmeter is developed to measure DC resistance in the range of 1 µΩ - 10 kΩ with test current up to 10А of:

Windings of power and instrument transformers, windings of electric motors, generators, linear compensators and windings of other high-inductive equipment;
Contacts of circuit breakers, resistors, buses and other non-inductive circuits;
Compensatory, current limiting and other resistors of high-voltage circuit breakers;
Сables.

Test current range is specified both in automatic and manual modes; resistance measurement range is set automatically. The instrument ensures fully automated resistance measurement under highly inductive load and thermal EMF balancing in external circuit.

Watch detailed video-reviews about MIKO-8M(A) milli-ohmmeter up above or on our YouTube. Watch videos and subscribe.

MIKO-8M(A) implements specialized measurement modes for various configurations of 11 objects (resistive object, inductive object, voltage transformer, current transformer and power transformer, generator, electric motor, reactor, compensator, connection filter and magnet), taking into account their specific features, while the user can select a standard object from the list, or create his own object.

The instrument automatically takes into account the configuration of the object to adjust the measuring modes.

Depending on the object type, you can select special measurement modes. For example, for a resistive object:

AUTO: the measurement starts automatically by the circuit closing.
SINGLE: the measurement starts upon the user's command (by pressing the START button).
PERIOD: the measurement starts automatically in prespecified time intervals.

For an inductive object, the user can also select one of two modes:

MANUAL: start and stop of the measurement are conducted manually by pressing the START button.
AUTO 1Ph: the measurement is initiated by pressing the START button and stopped automatically, if criterium specified is reached.

AUTO 1Ph mode has SKB EP patented automatic measurement method that guarantees results with the highest accuracy.

It is achieved by setting the max test current in the measurement circuit not on a staggered basis (depending on the value of the measured resistance), but continuously w/o fixed measurement ranges in a wide load range.

This measurement mode provides high signal level in a complex electromagnetic environment of industrial production or substation. Moreover, in AUTO modes of the measurement process the instrument produces the highest test current that enables guaranteed saturation of the transformer magnetic system.

MIKO-8M(A) has a built-in archive of up to 1,000 measurements for viewing, copying or deleting data. And due to the possibility of choosing an object at the measurement stage, the results are presented more systematically. This feature facilitates interaction with the archive.

The group of MIKO-7M(A), MIKO-8M(A) and MIKO-9(A) instruments has a number of automatic recalculation functions:

Auto δ calculation of Rphase between one another.
Auto conversion of Rlinear to Rphase. Linear windings are Delta or Star without neutral connected.
Auto correction of R measured at t° to R at t°p taking into account the winding material.
Auto δ calculation between Rcorrected and Rp.
Auto calculation of t° by its R.

OLTC non-demountable check mode allows the user to assess the state of the switching OLTC equipment with current limiting resistors without removing contactor tank cover.

This mode involves measuring of instant test current values. Test current firstly passes through the transformer winding and then through OLTC contacts while switching from one tap to another. The DRM graph is built on the basis of the measurement results and shows current change during tap changing. This graph enables to check tap changing time and general object state.

Analysis of the acquired graphs enables not only to sort out OLTC by fault-free/faulty criteria, but also to define the nature of the defect eliminating the opening of fault-free OLTCs. Milli-ohmmeter mode and DRM test complement each other and provide the user comprehensive information about the transformer state.

An oscillogram of the contactor operation in non-demountable mode (DRM test) on the screen of the device

Scaling the previous oscillograms and displaying the difference in the ordinates of two cursors (device’s screen)

MIKO-8М(A) has the safety certificate IEC 61010-1. The instrument also meets the requirements of electromagnetic compatibility that are applied to class A instruments according to IEC 61326-1.

The instrument has a high degree of protection against:

test cable or mains cable breakdown;
excess of test current;
EMF of self-induction;
overheat of the test block.

At disconnection of the test 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(A) is characterized by the redundant protection against EMF of self-induction in case of involuntary disconnection of the test cable or mains cable protecting users from electric shock and the instrument from being damaged.

MIKO-8M(A) is equipped with a color graphic touch screen display of high brightness and an intuitive interface, which facilitates interaction with the device.

Management can be carried out through the keyboard, touch screen or from a special mobile application that allows you to maintain and synchronize the enterprise measurement database from the instrument, and also makes it possible to control the device remotely.

None of the test cables is included to the standard complete set of MIKO-8M(A) device. This allows the customer to choose exactly required cables.

For user's choice and the convenience of connecting to the object, there are special test cables designed of different lengths and different types of clamps/fasteners:

10A Kelvin Clamp test cable 1 x 8.5 m (jaw up to 80 mm);
10A Kelvin C-clamp test cable 1 x 8.5 m (jaw up to 103 mm) for connection to transformer;
10A Kelvin Clamp test cable 1 x 4 m (jaw up to 25 mm) for resistance measurement of CT and VT windings;
10A Kelvin test cable 1 x 3 m (0.5 kg) with 2 probes and 4 crocodile clips (jaw up to 25 mm) (length: 70 mm, plug: 3 mm) for contact resistance measurement of CT and VT contact joints and windings.

Test cable SKB041.18.00.000 (on order)

Test cable SKB041.22.00.000 (on order)

Test cable SKB041.26.00.000 (on order)

Test cable SKB041.21.00.000 (on order)

Test cable SKB041.19.00.000 (on order)

For customer’s choice the MIKO-8M milli-ohmmeter has two modifications: with a built-in battery (MIKO-8MA) and without a built-in battery (MIKO-8M). The device can also be powered from the mains (AC 90-253 V, 47-63 Hz // DC 127-354 V).

Specifications	Value
Resistance range	1 μΩ - 10 kΩ
Resolution capability	0.1 μΩ
Accuracy	±(0.1%+0.5 μΩ)
Test current output	0,001 A - 10 A
Test current range in DRM mode	0.1 A - 10 A
Measurement display resolution	5 digits
MIKO-8MA: Power supply (built-in battery)	Li-ion battery
MIKO-8MA: Battery charge time	3 hours
MIKO-8MA: Battery runtime (in continuous operation) with output capacity 1W	8 hours
Built-in memory	up to 1,000 measurements
PC connection	USB cable and Bluetooth
Display	Color graphic TFT touch, 800 x 480 pixels
Power consumption	120 W
Output capacity, W	60 W
Power supply (mains voltage)	90-253 V AC, 47-63 Hz 127-354 V DC
Dimensions	270 х 250 х 130 mm
MIKO-8MA: Main instrument weight with battery	4.0 kg
MIKO-8M: Main instrument weight without battery	2.7 kg
Operating temperature range	-20ºС - +55ºС
Environmental protection with open cover	IP40
Environmental protection with closed cover	IP67
Interface and user manual language	English
Testing period	3 years
Calibration period	3 years
Warranty period	3 years

Standard complete set

Photo	Item, Index	Application
MIKO-8M or MIKO-8MA main instrument 049.00.00.000 or 049.00.00.000-01	MIKO-8M or MIKO-8MA main instrument 049.00.00.000 or 049.00.00.000-01	Instrument and documents: User Manual and a Log Book.
Test cables on order	Test cables on order	As a matter of convenience for the user, test cables are not included to the standard complete set. Each user can select a cable to his/her own requirements. Please, select at least one test cable (see "additional complete set on order" below).
Mains cable 018.09.00.000	Mains cable 018.09.00.000	Mains cable 1 x 2 m. Weight 0.24 kg. For connecting the instrument to the power line. Temperature range -25°С - +120°С. Rubber insulation.
Ground cable 010.01.00.000	Ground cable 010.01.00.000	Ground cable 1 x 2 m. Weight 0.08 kg. For instrument grounding. The cable is equipped with a ground clamp and a screw end cap. Nominal test current – 50А.
Zero resistance standard 023.15.00.000	Zero resistance standard 023.15.00.000	Resistance zero point accuracy check. Value – 0.000 µOhm.
Shunt	Shunt	Type: 75ShSM M3 (75ШСМ М3). For checking MIKO-8M(A) operability. Value – 1 mΩ ±0.5%.
Fuses	Fuses	Type: VP2B-1V-2A (ВП2Б-1В-2А) (2 pcs). For the power source protection.
USB 2.0 A-B Cable	USB 2.0 A-B Cable	USB cable 1 x 1.8 m. For computer connection and data transfer.
Attachment devices set kit 126.06.02.000	Attachment devices set kit 126.06.02.000

Additional complete set (on order)

Photo	Item, Index	Application
Test cable 041.18.00.000	Test cable 041.18.00.000	10A Kelvin Clamp test cable 1 x 8.5 m (jaw up to 80 mm). Weight 1.72 kg. Elastic silicone tube resistant to low and high temperatures and corrosive media.
Test cable 041.22.00.000	Test cable 041.22.00.000	10A Kelvin Clamp test cable 1 x 8.5 m (jaw up to 80 mm) for connection to transformer bushings. Modification of the 041.18.00.000 cable. To be used on transformers with bushings located close to each other. Weight 1.72 kg. Elastic silicone tube resistant to low and high temperatures, and corrosive media.
Test cable 041.30.00.000	Test cable 041.30.00.000	10A Kelvin Clamp test cable 1 x 3.5 m (jaw up to 50 mm) for connection to transformer bushings. To be used on transformers with bushings located close to each other. Weight 0.76 kg. Elastic silicone tube resistant to low and high temperatures, and corrosive media.
Test cable 041.26.00.000	Test cable 041.26.00.000	10A Kelvin C-clamp test cable 1 x 8.5 m (jaw up to 103 mm) for connection to transformer. Weight 2.26 kg. Alternative version of 041.18.00.000 test cable. Elastic silicone tube resistant to low and high temperatures and corrosive media.
Test cable 041.19.00.000	Test cable 041.19.00.000	10A Kelvin test cable 1 x 3 m. Weight 0.5 kg. With 2 probes and 4 crocodile clips (jaw up to 25 mm) (length: 70 mm, plug: 3 mm) for contact resistance measurement of CT and VT contact joints and windings.
Test cables for CT and VT 041.21.00.000	Test cables for CT and VT 041.21.00.000	10A Kelvin Clamp test cable 1 x 4 m (jaw up to 25 mm) for resistance measurement of CT and VT windings. Weight 0.61 kg. Cable is used for CTs and VTs which are stand-alone or built into transformers / circuit breakers.
Test cable 041.29.00.000	Test cable 041.29.00.000	10A Kelvin Clamp test cable 1 x 3.5 m (jaw up to 80 mm) for connection to transformer bushings., to be used on transformers with bushings located close to each other. Weight 0.92 kg. Elastic silicone tube resistant to low and high temperatures, and corrosive media.
Test cable extension 031.20.00.000	Test cable extension 031.20.00.000	Extension cable 1 x 6.5 m. Weight 1.18 kg. Elastic silicone tube resistant to low and high temperatures and corrosive media. To be used together with test cables 041.18.00.000 (jaw up to 80 mm), 041.22.00.000 (jaw up to 80 mm) and 041.26.00.000 (jaw up to 103 mm).
Test cable 041.28.00.000	Test cable 041.28.00.000	10A Kelvin test cable 1 x 3 m, 0,54 kg, with spring-loaded probes. To be used for electrical resistance measurement in hard-to-reach places.
Short-circuiting cable (set of 3 pcs.) 041.23.00.000	Short-circuiting cable (set of 3 pcs.) 041.23.00.000	Short-circuiting cable set 3 x 3 m with crocodile clips (jaw up to 80 mm). Set weight 1.89 kg (0.63 kg + 0.63 kg + 0.63 kg). The set is used for applying the DRM-test by short-circuiting secondary circuits. This cable is for OLTCs of power transformers. Furthermore, this cable is needed for connecting the high-voltage and low-voltage windings when 2 windings mode is applied.
Short-circuiting cable (set of 3 pcs.) 035.31.00.000	Short-circuiting cable (set of 3 pcs.) 035.31.00.000	Short-circuiting cable set 3 x 12 m with crocodile clips (jaw up to 50 mm). Set weight 0.8 kg (0.27 kg + 0.27 kg + 0.27 kg). The set is used for applying the DRM-test by short-circuiting secondary circuits. This cable is for OLTCs of power and auto transformers.
Additional resistor 032.25.00.000	Additional resistor 032.25.00.000	For in-place OLTCs monitoring at total resistance of the winding of no more than 0.5 Ω. Length 0.11 m + 0.35 m. Weight 0.23 kg.
Adapter for a reference coil 023.12.00.000	Adapter for a reference coil 023.12.00.000	For testing laboratories: inspection / calibration of the instrument. Length 0.025 m + 0.16 m. Weight 0.04 kg.
Tool bag 126.06.00.000	Tool bag 126.06.00.000	Convenient, robust, wear proof bag for transportation of cables, documentation and other accessories to MIKO-8M or to MIKO-8MA instrument. Weight 0.6 kg.
Manipulating rod 010.41.00.000 010.41.00.000-01 010.41.00.000-02	Manipulating rod 010.41.00.000 010.41.00.000-01 010.41.00.000-02	Manipulating rod is designed for test cables connection from the ground or from the tank cover to the bushings of high-voltage circuit breakers, and to the structural elements of high-voltage disconnecting switches and earthing devices, without the use of ladders or elevated platforms. The manipulating rod is completed with special extension cables. There is a Kelvin clamp with current and potential contacts to connect to the object on one side, and a contact pad on the other side. The device test cable is connected to the contact pad from the ground or a tank cover. Manipulating rod extension cable is made according to a four-wire (Kelvin) scheme with the test current capacity of 100 A in the presence of a good contact. Manipulating rod - 2.2 (length 2.2 m / weight as an assembled set 3.4 kg); Manipulating rod - 3.7 (length 3.7 m / weight as an assembled set 4.0 kg); Manipulating rod - 5.1 (length 5.1 m / weight as an assembled set 4.6 kg).

TESTS (2)

Full List

Why is it important to short-circuit the secondary windings when diagnosing OLTC?

We explain the need to short-circuit the secondary windings of the transformer during non-demountable diagnostics of OLTC devices (DRM)

19 september 2023

Report upon operation of MIKO-8 MegionEnergoNeft, LLC

In May, 2018 MegionEnergoNeft, LLC took milliohmmeter MIKO-8 for a trial operation.

22 august 2018

Articles (6)

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Comparison of SKB EP milli-ohmmeters

SKB EP company implements three specialized instruments for DC resistance measurement in inductive objects - MIKO-7M(A), MIKO-8M(A) and MIKO-9A, as well as a universal instrument for inductive and non-inductive objects - multipurpose low / high resistance meter MIKO-2.3

21 june 2022

Comparison of SKB EP transformer OLTC diagnostic systems

SKB EP company implements 2 specialized instruments for OLTC diagnostic - PKR-2 and PKR-2M, as well as 2 instruments MIKO-9A and MIKO-8M(A), where diagnostic of this mechanism is realized as an additional mode. In the summary comparison table, the differences between the instruments are considered.

21 june 2022

Videos (2)

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Milli-ohmmeter MIKO-8M(A) with DRM mode review

MIKO-8M(A) is designed to measure DC resistance in inductive and non-inductive circuits. Is equipped with a non-demountable estimation of OLTCs mode. More information can be found in the review and on website of manufacturer.

Milli-ohmmeter MIKO-8M(A)

DC current resistance measurement in inductive and noninductive circuits in the range from 1 µOhm ÷ 10 kOhm for the current of up to 10А.

MIKO-8M(A) CE Conformity Certificate; valid until 02.08.2025

МIКО-8М - EAC № RU Д-RU.PA03.B.34601/22; valid until 28.04.2027

МIКО-8М(А) is included in Russian State Register under #72766-18, valid until 16.10.2029

Open Original
- Review about:
- Advanced HV circuit breaker analyzer PKV/M7
- Advanced precision milli-ohmmeter MIKO-9A
- Compact micro-ohmmeter MIKO-10
- High precision micro-ohmmeter MIKO-21
- Industrial micro-ohmmeter MIKO-1
- Milli-ohmmeter MIKO-7M(A)
- Milli-ohmmeter MIKO-8M(A)
- Multipurpose low / high resistance meter MIKO-2.3
- Universal HV circuit breaker analyzer PKV/U3.1
Yamalo-Nenets enterprise of the main power networks the branch of FGC UES, PJSC

Yamalo-Nenets enterprise of the main power networks the branch of FGC UES, PJSC thanks your company SKB EP, LLC for the fruitful cooperation in the supply of measuring instruments for the diagnostic of high-voltage equipment. We also thank you for prompt, professional work and individual approach, as well as for the high quality of instruments and its components.

Our company operates such instruments as MIKO (10 pcs.), and PKV (10 pcs.) manufactured by SKB EP, LLC.

These instruments are used to determine repair quality of high-voltage circuit breakers and disconnecting switches. The contact resistance of the current-carrying circuit, the time and speed characteristics of HV circuit breakers are checked with a help of them.

The instruments are very convenient, they give an opportunity to identify the worsened condition of contact connectors on HV circuit breakers and of disconnecting switches. They reduce the time for detecting a defect and prevent accidents and technological disturbances. The defects are periodically identified. That fact allows us to schedule a necessary repair work on time and maintain the equipment in a good working condition.

We recommend these instruments for use in organizations, which operate high-voltage equipment.

Thank you for your help in solving our production tasks and sincerely hope for further mutually beneficial cooperation.

S.I.Kandiano
Acting Chief Engineer-Deputy Director
Open Original
- Review about:
- Compact micro-ohmmeter MIKO-10
- High precision micro-ohmmeter MIKO-21
- Milli-ohmmeter MIKO-8M(A)
Urengoy branch of Gazprom Energo, LLC

Since 2017 Electrotechnical laboratory of the Urengoy branch of Gazprom Energo, LLC has been operating MIKO-10 and MIKO-21 micro-ohmmeters and also MIKO-8M(A) milli-ohmmeter. These devices are used to measure the resistance of switching devices, power and measuring transformers, and electric motors.

The advantages of the operated devices include small dimensions and weight, the presence of built-in power sources in MIKO-10 and MIKO-21 micro-ohmmeters, a simple and intuitive interface.

[Manufacturer note]: MIKO-8M(A) milli-ohmmeter also has a built-in power supply. It can be supplied both without a battery: MIKO-8M version, and with it: MIKO-8MA version.

During the operation, all devices have proven themselves on the good side, there are no malfunctions or failures. In comparison with the previous versions of measuring devices, MIKO-10, MIKO-21 and MIKO-8M(A) have become more efficient, which allows, in addition to the high accuracy of the measurements obtained, to reduce the work time due to the simpler assembly of the measurement circuit.
Open Original
- Review about:
- Milli-ohmmeter MIKO-8M(A)
Condensate Stabilization Plant named after V.S. Chernomyrdin (Surgut CSP) the branch of Gazprom Pererabotka, LLC

Our plant has been using MIKO-8 milliohmmeter since 2016. The device is built into a good strong case that is convenient for transportation. During the time of use, with the help of MIKO-8 were diagnosed more than 100 units of electrical equipment (transformers, electric motors of various capacities and other equipment). One of the main advantages for our staff was the ability of automatic recalculations of deviations with indication of parameters and their saving into the device memory. The second advantage is the possibility of further processing of measurement results on a PC using specialized software. Also, among the advantages we can highlight the measurement speed, intuitive operation of the device, and its small dimensions.

Among the disadvantages, we note the use of non-standard connectors on the test cables and the inability to use third-party cables, the lack of auto power selection of the device.

[Manufacturer note]: Cable connectors that are implemented in our devices actually involve the use of the cables only of our production. Thereby we guarantee the reliability of the devices that you use, and we are responsible for the results that you get during measurement process. Unfortunately, when using third-party cables, we cannot guarantee the correctness of the data obtained.
The possibility of auto power selection is implemented in the upgraded versions of our milliohmmeters, more information about their characteristics can be found via the link. In addition, in modern milliohmmeters, the power can be set both automatically and manually.

MIKO-8 copes well with the assigned tasks. We can recommend it to other companies.

We allow you to post this review on the website and to use it for advertising purposes.
Open Original
- Review about:
- Milli-ohmmeter MIKO-8M(A)
Saint-Petersburg Metro

During the operation since November 2020, no malfunctions have been detected. As a whole, the instrument has shown high reliability in the harsh working conditions of the Metro and is characterized by high quality, modern technical solutions and functionality.

The main advantages of the instrument include: high precision of measurements, a large range of measured current values, high autonomy, a big bright informative screen, a shockproof housing, a useful carrying handle and a convenient calibration period.

P.V.Dankov
Deputy Head
Open Original
- Review about:
- Milli-ohmmeter MIKO-8M(A)
- Transformer OLTC diagnostic system PKR-2M
Branch of IDGC of Center, PJSC - Kurskenergo

In the Western Section of the Diagnostic Service of Rosseti Kurskenergo, PJSC, 2 measuring instruments of SKB EP, LLC are used: PKR-2M instrument for control of OLTC devices of transformers and milli-ohmmeter MIKO-8M. The PKR-2M instrument has been used since 2018, the MIKO-8M instrument has been used since 2019.

These instruments are used for diagnostic of power and measuring transformers with a voltage of 110, 35, 10 kV (MIKO-8M), OLTC devices of power transformers 110, 35 kV (PKR-2M).

In practice, both instruments have proven themselves from the best side: they have a compact, durable body, an intuitive and user-friendly interface. There is an opportunity to select the necessary circuits and groups of connection of windings, create and maintain an archive, including the possibility of entering factory tests, this allows to conduct a primary analysis of diagnostic results directly at the workplace, they have high-quality execution of wires, clamps and there is opportunity to adjust the complete set. In comparison with the previously used instrument assortment, all these significantly reduce time and labor expenditures during equipment diagnostic. Also, we would like to note the availability of software for analyzing and storing diagnostic results on a PC and the opportunity to get the necessary information and (or) advice directly from the instrument developers.

Shirlin I.V.
Head of the Western Section of the Diagnostic Service
Open Original
- Review about:
- Advanced HV circuit breaker analyzer PKV/M7
- Milli-ohmmeter MIKO-8M(A)
Kumerautskaya CHP, LLC

We inform you that the instrument PKV/M7 (prod. N2 53, 2012), milli-ohmmeter MIKO-8M (prod. N2 035J, 2018) manufactured by SKB EP, LLC (Specialized Design Bureau of Electrotechnical Instrumentation, LLC) are in operation at Kumerautskaya CHP, LLC.

With the PKV/M7 instrument, diagnostic and checking of electrical characteristics of high-voltage circuit breakers are carried out at the station, and the MIKO-8M milli-ohmmeter is used to measure DC resistances of windings and coils of electrical equipment, contact resistances of high-voltage circuit breakers and electrical equipment.

Owing to the fact that the instruments are realized on the basis of microprocessor technologies, it has become much more convenient and efficient to carry out measurements, the accuracy of measurement results and safety have increased, and archiving has become possible.

E.A. Shevchenko
Deputy Chief Engineer - Head of the Technical Department of Kumertautskaya CHP, LLC
Open Original
- Review about:
- Industrial micro-ohmmeter MIKO-1
- Milli-ohmmeter MIKO-8M(A)
EnergoSK, LLC

The company EnergoSK, LLC, the department of the electrotechnical laboratory, currently performs tests and measurements at the Amur TPP.

The applied instruments of your production: MIKO-1 micro-ohmmeter, MIKO-8 milli-ohmmeter.

We have been using these instruments since 2011, there are no complaints.

MIKO-1 is used for measuring the contact resistances of high-voltage circuit breakers, busbars, etc. The instrument works reliably, quickly with high measurement accuracy.

MIKO-8 is used in measuring the resistances of windings in power transformers, current and voltage transformers, electric motors, generator stators and rotors. The instrument operates at a high measurement speed that greatly saves measurement time.

The instruments have been just tested for all the years of operation. There have been no breakdowns.

I recommend you using these instruments, as I have been used them myself for many years!

Kim A.A.
The chief ETL specialist
Open Original
- Review about:
- Milli-ohmmeter MIKO-8M(A)
MegionEnergoNeft, LLC

In May 2018, MegionEnergoNeft LLC received a pilot operation of the MIKO-8 device for measuring the direct current resistance of windings of oil and dry transformers from 0.4 to 110 kV of various types and designs. The device was operated both during the repair of electrical equipment during the repair of power transformers, and at transformer substations in the course of acceptance tests of electrical equipment serviced by MegionEnergoNeft LLC.

During exploitation, the advantages of the instrument were revealed, for example: small dimensions, a convenient housing for transportation and operation, an intuitive menu, a built-in measurement archive that allows you to speed up the measurement, simplify the processing of the results and automatically recalculate the data. Measurements are carried out in a short time, which in comparison with other devices significantly reduces the time of measurements. A positive feature of MIKO-8 is the ability to measure the resistance of the windings of power transformers with on-load tap-changers without disconnecting the device from the network and the equipment being measured, which significantly reduces the time it takes to take measurements.

Information is displayed on a large contrast screen that allows readings without voltage. During operation, no shortcomings were detected, the device works flawlessly.

As wishes for additional equipment, there is not enough portable compact battery pack with a built-in charger and a plug for connecting in the field [Manufacturer comment: The MIKO-8 millimeter is discontinued – in its place is a new modification of the MIKO-8M / MIKO-8M(A) (with built-in battery)].

According to the results of trial operation, it was found that this instrument meets the declared characteristics and significantly superior to instrument of a similar purpo
Open Original
- Review about:
- Milli-ohmmeter MIKO-8M(A)
Slutsk Electric Networks (RUE Minskenergo)
We have been operating MIKO-8M(A) milliohmmeter for two years, and the advantages of the device are the following:
- portability;
- compact size;
- informative menu;
- availability of the DRM test;
- possibility of use on high-inductive equipment.
The disadvantage is a small internal memory for information storing.

MIKO-8M(A) milliohmmeter deserves a high rating according to its characteristics. We are looking forward to new developments.
Open Original
- Review about:
- Milli-ohmmeter MIKO-8M(A)
TESS Siberia, LLC
We have been using MIKO-8M(A) for two months. And the following positive advantages were revealed during the operation process:
1. Built-in rechargeable battery allows to make measurements without connecting the device to the network.
2. Checking the continuity of the measurement circuit of the object allows you to make sure that the device is connected correctly.
3. The presence of the multi-touch screen and buttons ensures reliable control of the device.
4. Extended resistance range up to 10 kΩ (comparing to MIKO-7) allows to measure resistance of the voltage transformer windings.
5. The presence of the archive ensures convenient processing of the numerous measurement results in various objects.
Revealed remarks:
1. The inscription "Measurement in progress, do not break the circuit" is too small, hardly noticeable in sunlight (it is worth increasing the font of all inscriptions).
2. It is necessary to increase the volume of the sound signal, because in conditions of heightened noise level it is not audible (in MIKO-7 the sound signal is much stronger).
3. For the convenience of typing on the keyboard, please add a virtual QWERTY keyboard.