High precision micro-ohmmeter MIKO-21

Certificates

  • Safety Test Certificate IEC 61010-1:2001
  • Conformity certificate with safety requirements EC/EU
  • Russian State Register Certificates
  • Declaration of Conformity of the Customs Union
  • Russian Register of Innovative Products
  • Recommended for use in JSC Russian Railways electric installations
  • PJSC ROSSETI Register of Innovative Solutions

Wide functionality and high accuracy ±0.05%

More

Adjustable test current up to 200 A

More

Special algorithms for measuring contact resistance of HV circuit breakers with built-in current transformers (CT)

More

4 ways of resistance measurement start-up

More

Automatic storage of measurement results

More

Automatic indication of measured resistance thresholds

More

Color graphic touch-screen display, intuitive interface

More

Battery-operated power supply, light weight and size

More

Variable instrument complete set

More

MIKO-21 is designed for high precision measurements of DC electrical resistance in the range from 0.1 µΩ to 2 Ω with an accuracy of ±0.05% and can test:

  • contacts of high-voltage circuit breakers of all types and voltage classes;
  • contactors, relays, busbars, various bolted connections, welded joints, brazed joints;
  • elements of equipment for open and closed switchgears in extreme electric and magnetic field conditions;
  • in research laboratories and industrial workshops.

MIKO-21 is ahead of similar devices represented on the market due to a number of functional and technical features. For example, special measuring technologies ensure MIKO-21 compliance with the most stringent accuracy requirements. MIKO-21 is ideally applicable for high precision resistance tests in the µΩ range.

Please watch detailed video-reviews about MIKO-21 micro-ohmmeter up above or on our YouTube. Watch videos and subscribe.

One of the problems during contact resistance measurement with permissible error is availability of oxide films between contact surfaces.

According to international standard IEC 60694: General Specifications for High-Voltage Switch Gears (International Electrotechnical Commission), to control this type of error test current amperage during testing the electric resistance in the main circuit of a HV circuit breaker shall be between 50 A and its rated value.

Test current in circuit breakers is often limited by specific values: 100 A and 200 A.

The amperage in MIKO-21 can be set in several ways:

  • By selecting from a number of specified values: 10 A, 50 A, 100 A, and 200 A;
  • By setting the automatic mode for selecting test current;
  • By setting test current manually in the range from 1 A to 200 A at a step of 1 A.

SKB EP micro-ohmmeters are the only instruments enabling to measure contact resistance of live tank and dead tank circuit breakers using separate automatic modes optimized for those circuit breakers.

  • Mode 1 makes it possible to carry out measurements in the circuits without CT;
  • ­Mode 2 enables to operate measurements in the circuits with CT with minimal battery power consumption;
  • Mode 3 enables to operate measurement in the circuits with CT using 100 A or 200 A test current (set by a user) without saving battery power.

Current transformers of dead tank circuit breakers form an extended transition process when test current is applied. Due to that measurement time is determined by the parameters of CTs, their number, and test current. For example, for HV oil-blast circuit breakers measurement time may be up to 30 seconds.

MIKO-21 special algorithms with automatic measurement stop prevent subjective errors and increase number of measurements per one battery charge.

Four ways are programmed in the instrument to start resistance measurement:

  • Single is started once the cable clamps are contacted to the tested object and followed by pressing the START button.
  • Auto single circuit is initiated by pressing the START button. The instrument will start measurement when the electric contact between the tested circuit and the test cable contacts is set. The test can be repeated by pressing the START button again.
  • Periodic is used in pre-specified time intervals when both hands are occupied with cable probes pressing against the test points. The user can choose time interval between the tests. The instrument will work continuously until the user stops the mode.
  • Auto periodic circuit is initiated by pressing the START button and used for continuous measurements. The user connects the current cable, and as soon as the potential contacts are connected, the measurement will start automatically. To repeat a test, simply break contact with potential probes and reconnect.

The instrument contains a built-in database that contains nominal values of high-voltage circuit breakers indicating the maximum and/or minimum permissible values ​​of contact resistance. There are also the nominal values for rejected resistors indicating the acceptable values ​​of the upper and lower thresholds of resistance.

The user can add / edit / delete the nominal values ​​of the exact measured object.

Availability of a built-in archive of nominal values of electric resistances (main circuit resistance of HV circuit breakers) facilitates automatic detection, and once the measured value exceeds the nominal value it is highlighted with red colour.

This mechanism works due to either the built-in database of nominal values or the ability to add / edit / delete the nominal data of the measured object independently.

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

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

Communication with PC via USB or a flash card facilitates data transfer from the Instrument to the company data base. The device can be integrated into measuring systems under PC control of diagnostic laboratories and companies producing electric equipment.

Battery power, low weight and small dimensions ensure complete independence and high mobility of the device in the vast territory of the substation or workshop, and the built-in memory for 2,000 measurements greatly simplifies the process of diagnostics and data transfer from the substation into the company office.

For convenient connection to the object, there are special test cables of different lengths and different types of clamps:

  • Test cables with Kelvin clamps for high voltage circuit breakers up to 110 kV 2 m long (standard complete set);
  • Test cables with Kelvin double hand spikes 1.5 m long for measurement in pipelines and interrupting chambers (recommended when the device is placed near the circuit breaker);
  • Test cables with Kelvin C-clamps for circuit breakers from 10 kV to 220 kV 4.5 m and 6 m long (recommended when the device is placed near the circuit breaker);
  • Test cables that consist of a cable with Kelvin clamp and Kelvin C-clamp for circuit breakers from 220 kV to 750 kV 3m / 6m or 9m long (recommended when the device is places in a cradle of a lift);
  • Test cable for precise measurements and measurements on sections of the electric circuit, to the end points of which the test current is applied.
Specifications Value
Resistance range, Ohm 0.1 µΩ - 2 Ω
Current range, A 1 - 200
Number of digits in the output of the measurement result 5
Accuracy ±0.05 %
Time of measurement in Mode 1, sec not more than 2
Time of measurement in Mode 2 on a dead tank circuit breaker with a built-in CT (energy saving), sec 10 - 30
Time of measurement in Mode 3 on a dead tank circuit breaker with a built-in CT (without energy saving), sec 5 - 15
Mains voltage AC 90-264, 47-63 Hz
DC 127-370 V
Consumed power does not exceed, W 60
Battery type Li-Ion
Battery lifetime (in continuous operation), hrs more than 8
Battery recharge time, hrs less than 2
Built-in memory 2,000 measurements
Number of tests (max. current, I=200A) more than 500
PC communication USB / USB Flash
Display Color graphic display,
touch-screen, 480 x 272 pix
Interface, User manual language English
Environmental protection with closed cover IP 67
Environmental protection with open cover IP 40
Storage temperature, ºС -20 - +60
Operating temperature, ºС -20 - +50
Relative humidity, % (non condensing) 95
Dimensions, mm 270 х 246 х 124
Test block weight, kg (lbs) 3.3 (7.28)
Testing period, years 3
Calibration period, years 3
Warranty period, years 3

Standard complete set

Photo Item, Index Application
Main instrument<br>MIKO-21
  • Main instrument
    MIKO-21
  • SKB039.00.00.000
  • Main instrument
    MIKO-21
  • SKB039.00.00.000

Instrument and additional documents: Calibration Certificate, User Manual, Log Book.

Test cables<br>Set #2
  • Test cables
    Set #2
  • SKB039.27.00.000
  • Test cables
    Set #2
  • SKB039.27.00.000

200 A Kelvin clamp test cable 2 x 2 m (1.12 kg) with jaw up to
50 mm, for circuit breakers of up to 10kV.

Mains cable
  • Mains cable
  • SKB018.09.00.000
  • Mains cable
  • SKB018.09.00.000

Mains cable 1 x 2 m (0.24 kg). For instrument connection to the mains. Operating temperature range -25°С - +120°С. Rubber insulation.

Ground cable
  • Ground cable
  • SKB010.01.00.000
  • Ground cable
  • SKB010.01.00.000

Ground cable 1 x 2 m (0.07 kg) for instrument grounding. The cable is equipped with a C-clamp and a screw end cap. Rated current is 50 А.

Shunt
  • Shunt
  • Shunt

Type: 75ShSM M3 (75ШСМ М3). For checking MIKO-21 operability.

Fuses
  • Fuses
  • Fuses

Type: VP2B-1V-2A (ВП2Б-1В-2А) (2 pcs). For the power source protection.

Tool bag
  • Tool bag
  • SKB126.06.00.000
  • Tool bag
  • SKB126.06.00.000

Convenient, robust, wear proof bag for transportation of cables, documentation and other accessories to MIKO-21.

Test cables, if the instrument is placed near the circuit breaker (on order)

Photo Item, Index Application
Test cables<br>Set #1
  • Test cables
    Set #1
  • SKB039.19.00.000
    SKB039.19.00.000-01
  • Test cables
    Set #1
  • SKB039.19.00.000
    SKB039.19.00.000-01

200 A Kelvin double hand spike test cable 2 x 1.5 m (0.9 kg) for measurements in busbars or in arc extinguish chambers.

Test cables<br>Set #3
  • Test cables
    Set #3
  • SKB039.25.00.000
  • Test cables
    Set #3
  • SKB039.25.00.000

200 A Kelvin С-clamp test cable 2 x 4.5 m (3.8 kg) with jaw up to
80 mm, for all the circuit breakers of up to 35 kV, and for some circuit breakers of up to 110 kV.

Test cables<br>Set #4
  • Test cables
    Set #4
  • SKB039.26.00.000
  • Test cables
    Set #4
  • SKB039.26.00.000

200 A Kelvin С-clamp test cable 2 x 6 m (5.6 kg) with jaw up to
80 mm, for all the circuit breakers of up to 110 kV and some circuit breakers of up to 220 kV.

Test cable
  • Test cable
  • SKB039.24.00.000
    SKB039.24.00.000-01
    SKB039.24.00.000-02
  • Test cable
  • SKB039.24.00.000
    SKB039.24.00.000-01
    SKB039.24.00.000-02

Optional potential test cable with crocodile clips A25C (2 pcs) and probes (2 pcs) for precise measurements and for measurements on the sections of the electric circuit, to the end points of which the test current is applied.

  • To be used together with Set #2 - Length 2 m (SKB39.24.00.000)
  • To be used together with Set #3 - Length 4.5 m (SKB39.24.00.000-01)
  • To be used together with Set #4 - Length 6 m (SKB39.24.00.000-02)

In particular, the cable can be used in case of measurement of cables resistivity.

Test cables
  • Test cables
  • 041.28.00.000
  • Test cables
  • 041.28.00.000

10A Kelvin test cable 2 x 2.5 m with spring-loaded probes. To be used for electrical resistance measurement in hard-to-reach places.

Test cables, if the instrument is placed in the lift cradle (on order)

Photo Item, Index Application
Test cables<br>Set #5
  • Test cables
    Set #5
  • SKB039.20.00.000
    SKB039.21.00.000
  • Test cables
    Set #5
  • SKB039.20.00.000
    SKB039.21.00.000

Test cable kit for circuit breakers of up to 220 kV.

  • 200 A Kelvin clamp test cable 1 x 1 m (0.5 kg) with jaw up to 50 mm.
  • 200 A Kelvin C-clamp test cable 1 x 3 m (1.3 kg) with jaw up to 70 mm.

Test cables<br>Set #6
  • Test cables
    Set #6
  • SKB039.20.00.000
    SKB039.21.00.000
  • Test cables
    Set #6
  • SKB039.20.00.000
    SKB039.21.00.000

Test cable kit for circuit breakers of up to 330 kV, and some of up to 500 kV.

  • 200 A Kelvin clamp test cable 1 x 1 m (0.5 kg) with jaw up to 50 mm.
  • 200 A Kelvin C-clamp test cable 1 x 6 m (2 kg) with jaw up to 70 mm.

Test cables<br>Set #7
  • Test cables
    Set #7
  • SKB039.20.00.000
    SKB039.21.00.000-02
  • Test cables
    Set #7
  • SKB039.20.00.000
    SKB039.21.00.000-02

Test cable kit for circuit breakers of up to 750 kV.

  • 200 A Kelvin clamp test cable 1 x 1 m (0.5 kg) with jaw up to 50 mm.
  • 200 A Kelvin C-clamp test cable 1 x 9 m (4 kg) with jaw up to 70 mm.

Additional accessories (on order)

Photo Item, Index Application
Potential spring-loaded contact (2 pcs.)
  • Potential spring-loaded contact (2 pcs.)
  • SKB023.21.00.000
  • Potential spring-loaded contact (2 pcs.)
  • SKB023.21.00.000

To be used together with sets ##2-7 for avoiding high contact resistances between an input pin and a clamp of the device.

Potential probe (2 pcs.)
  • Potential probe (2 pcs.)
  • SKB023.22.00.000
  • Potential probe (2 pcs.)
  • SKB023.22.00.000

To be used together with sets ##2-7 for avoiding high contact resistances between an input pin and a clamp of the device.

USB 2.0 A-B Cable
  • 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.

Manipulating rod
  • Manipulating rod
  • SKB010.41.00.000
    SKB010.41.00.000-01
    SKB010.41.00.000-02
  • Manipulating rod
  • SKB010.41.00.000
    SKB010.41.00.000-01
    SKB010.41.00.000-02

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 rod is completed with Kelvin clamps with current and potential contacts connected by the measurement pad. Test cables are connected to the pad from the ground or a tank cover.

Modern microohmmeter MIKO-21
  • Open Original

    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

    Altyntau Kokshetau, Ltd.

    Since 2017, we have been measuring resistance of the main circuits of high-voltage column and tank circuit breakers with the help of MIKO-21 microohmmeter.

    Advantages of the device: intuitive and easy-to-use interface, touch-screen color display, small dimensions and weight, a wide range of manually set values of the test current, the ability to transfer measurement results to the computer. MIKO-21 works both from the 230V network and from the built-in power supply. The complete set of the device assumes the possibility of choosing different test cable options.

    During the operation, there were no failures or malfunctions in the operation of the microohmmeter.

  • Open Original

    Kuban MEN the branch of FGC UES, PJSC

    I would like to inform you that in the branch of FGC UES, PJSC - Kuban CMEN uses MIKO-1, MIKO-2.3, MIKO-10, and MIKO-21 microohmmeters.

    During the operation, MIKO-group devices have proven themselves to be the best in terms of reliability, ease of use and accuracy of the results obtained on the state of the switching equipment (circuit breakers, disconnectors). The devices are also good at resistance measurement of pressed connections, resistance measurement of transformer windings. The devices are easy to transport (there is a special carrying bag), they are convenient to use due to the small size and built-in power supply.

    Among the disadvantages there is the lack of crocodile clips (or clamps) in the standard complete set for connecting to a large-section busbar (rigid busbar, hollow wires).

    [Manufacturer note]: Device complete set includes those cables that are most often used on various types of objects. Cables that help to measure resistance on large-section busbars are unfortunately used not as often, so they are included to the additional complete set of the devices and are available by request.

    Devices manufactured by SKB EP, LLC gave a good account of themselves and can be recommended to the companies performing adjustment or repair works, testings and measurements.

  • Open Original

    COMPANY LIMITED DIMITROVGRADSKY METALLURGICAL PLANT

    On July 1-2 Dimitrovgradsky metallurgical plant, LLC was testing the MIKO-21 microohmmeter. The instrument was used for measuring the electric resistance of copper items.

    MIKO-21 is a convenient multi-functional instrument with user-friendly menu. One of its merits is a large range of manually set values of test current and an option of data downloading to PC. Touch color display, an archive of passport values of tested equipment, independent power supply and small size are also worth mentioning. The instrument demonstrated proper operation, there were no failures.

  • Open Original

    ELMASH (UETM), LLC

    In the first quarter of 2017,  ELMASH (UETM), LLC (Yekaterinburg City), a research and testing division of BBA Production Complex performed pilot operation of MIKO-21 microohmmeter manufactured by SKB EP, LLC.

    The microohmmeter was used for measuring the transient resistance of the main circuits of high-voltage column-type and bulk-oil circuit breakers of ВГБ-УЭТМ®-35, ВГТ-УЭТМ®-110, ВЭБ-УЭТМ®-220 types.

    We should like to note the following merits of the microohmmeter: simple and user-friendly interface, touch display, small size and light weight, availability of the option of connecting the device to PC. Microohmmeter can be powered both from the 230V network and from an in-built battery that is a big advantage since devices are often used far from the available power sources.

    The device’s kit allows a large variety of options. During pilot operation the microohmmeter proved to be a reliable and convenient device. There were no failures observed.

  • Open Original

    JSC Moscow Helicopter Plant named after M.L. Mil

    In 2016, following the request of OJC MVZ named after M.L. Mil, SKB EP, LLC developed a new line of MIKO-21 microohmmeter specifically for solving the tasks of our Company.

    Using MIKO-21, OJSC MVZ named after M.L. Mil performs measurements of transient resistances of:

    • Aircraft equipment and helicopter fuselage;
    • Wire terminations in cap fittings and couplings.


    Test operation of MIKO-21 in 2016 revealed certain drawbacks in the device’s design and software that were completely eliminated by the Manufacturer.

    Since 2017 the MIKO-21 of special complement has been regularly used by JSC MVZ named after M.L. Mil and proved to be an instrument reliable and convenient in operation that fully replaces similar obsolete devices.

    The main merit of MIKO-21 microohmmeter is its simple and understandable interface, sensor display, small size and low weight, options of being powered from 220V, 50 Hz networks and from an in-built battery.

    There were no failures during the period of its operation.

  • Open Original

    Federal Network Company of Single Energy System

    That PAO FSK EES Branch operates the following instruments: MIKO-1 (16 pcs.), PKV/M7 (6 pcs.), PKV/M6 (4 pcs.), PKV/U3.1 (1 pcs.), MIKO-21 (1 pcs.).

    First instruments were procured in 2010. The instruments were used for monitoring and diagnosis of electric equipment at 220 and 500 kV substations.

    MIKO-1 device is rather convenient in use as it is powered from an in-built battery; it has small weight and size. It can be easily connected to any measured equipment owing to cable with clamps of two types. The process is easily controlled, measurements are of high accuracy; capacity of the in-built battery is sufficient for a large number of measurement sessions.

    We used PKV/M6 and PKV/M7 instruments for recording the time and speed characteristics of circuit breakers U-110, MKP-110, U-220, VMT-110, VMT-220, MKP-35, C-35, and of 6-10kV oil circuit breakers. The process of connection and diagnosis is rather simple.

    We recommend PKV/M6 and PKV/M7 instruments to all the companies dealing with maintenance and operation of electric equipment and to electric network companies.
  • Open Original

    PJSC T Plus Sverdlovsk branch of "Novo-Sverdlovsk CHP"

    On October 21, 2019, SKB Electrotechnical Instrument Making LLC, in a classroom at the Novo-Sverdlovsk Thermal Power Plant, conducted a demonstration and demonstration measurements for MIKO and PKV instruments to employees of the electrotechnical laboratories of several stations of the PJSC T Plus Sverdlovsk branch of "Novo-Sverdlovsk CHP.

    The measurements were performed on the VGM-20 circuit breaker in conjunction with representatives of SKB EP: Konstantin Muravin, Gennady Kurov, Natalia Korneeva. The following devices were demonstrated: the MIKO-21 microohmmeter (transition resistance of the contacts was measured) and the control device for the high-voltage circuit breakers PKV / M7 (the characteristics of the stroke, speed, time, and also the timing of the contacts were taken).

    On 6 kV 5DV-A motors, designed to measure the active resistance of DC windings, the operation of millimeters MIKO-7M (A) and MIKO-9A have been shown.

    Instruments have proven themselves on the good side in terms of operation and accuracy, as well as measurement speed. We recommend them for purchase and operation.

  • Open Original

    Switchgear Design Bureau, LLC

    In 2017 - 2019, our company acquired three MIKO-21 instruments, which are successfully used to measure the transition resistance of various types of high-voltage circuit breakers production by our company.

    During the work, the following advantages were identified:

    1. Automatic start of measurements;
    2. The ability to independently adjust the current strength;
    3. Ability to work on mains or battery;
    4. The ability to control the device through the PC using the included software; 
    5. The ability to transfer and save data on the PC.

    Separately, we note the comprehensive technical support of the manufacturer of the device regarding its operation.

    We can confidently recommend the MIKO-21 instrument to other companies.

  • Open Original

    Power Authority of SUEK-Kuzbass, JSC

    In response to your request dated 02.07.2020, we inform you that the MIKO-21 microohmmeter ser.no. 021J has been operated in the electrical measuring laboratory of SUEK-Kuzbass, JSC Power Authority since 2019. The device was especially purchased to measure resistance of the main circuit contacts of high-voltage circuit breakers and disconnectors in order to detect defects and to reduce the probability of failure of switching devices caused by contacts resistance increase.

    The device might be definitely called convenient-to-use according to the presence of the in-built battery. The battery allows you to run measurements independently without connecting to the network. Moreover, the battery doesn’t require to be charged frequently. With intensive work, it is necessary to recharge the battery no more than once a week.

    The measurement accuracy of the device is high. With repeated measurements, the readings on the display are the same.

    When the opportunity comes, we plan to purchase one or two more MIKO-21 microohmmeters.

We use cookies. By continuing to browse the site, you agree to the processing of your personal data and the Privacy policy.