If you have any questions contact our manager 24/7:
ENG
Measurement of transient resistances of electric circuits in the range of 0.1 µΩ ÷ 2 Ω, current range up to 200A, accuracy ±0.05%
Measurements using the rated current up to 200A
Special algorithms for measuring the transient resistances of high-voltage circuit breakers with in-built current transformers
Four methods of resistance measurement start-up
Archive of passport values of tested equipment
Automatic comparison of measured and passport values of resistances
Interactive control
Independent power supply, light weight and size
Test cable of unique and ergonomic design

Modern microohmmeter MIKO-21

Certificates
  • Safety Test Certificate IEC 61010-1:2001
  • EMC Compatibility IEC 61326-1:2005
  • Conformity certificate with safety requirements EC/EU
  • Recommended for use in JSC Russian Railways electric installations
  • PJSC ROSSETI Register of Innovative Solutions
  • Russian State Register Certificates
  • Declaration of Conformity of the Customs Union
Measurement of transient resistances of electric circuits in the range of 0.1 µΩ ÷ 2 Ω, current range up to 200A, accuracy ±0.05%
  • in high-voltage circuit breaker contacts,
  • in disconnecting switches, separators, and short-circuiters,
  • in packaged switchgears,
  • in contact couplings,
  • in contactors, busbar relays and joints,
  • in bolted connections, braze joints, weld seams in outdoor and indoor switchgears up to 750kV in conditions of intense and highly complex electromagnetic environments.

 Miko-21 is ahead of similar devices represented on the market due to a number of functional and technical features.
Measurements using the rated current up to 200A

One of the problems faced when measuring the transient resistances 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), for controlling this type of error, amperage of the test current during testing the electric resistance in the main circuit of a HV circuit breaker shall be between 50A and its rated value.

Current amperage in the passport data of many foreign circuit breakers is most often limited by specific values: 100A and 200A.

Amperage in the MIKO-21 can be set in several ways:

  • By selecting from a number of specified values: 10A, 50A, 100A, and 200A;
  • By setting the automatic mode for selecting the  test amperage;
  • Manual mode for setting the test current in the range from 1 to 200 A at a step of 1A.
Special algorithms for measuring the transient resistances of high-voltage circuit breakers with in-built current transformers

Only SKB EP microohmmeters measure transient resistances (R transient) of minimum-oil and bulk-oil circuit breakers using separate automatic modes optimized for those circuit breakers:  

  • Mode 1. This mode allows measurement of electric resistance in the circuits without current transformers (CT). 
  • ­Mode 2. This mode allows measurement of electric resistance in the circuits with CT. 
  • Mode 3. This mode allows measurement of electric resistance in the circuits with CT. Mode 2 differs in that the measurements are performed at 100A or 200A current (setup by a user) without saving the battery energy. 

Current transformers of bulk-oil circuit breakers form a prolonged transition process when the test current is applied. For this reason the time of measurement is determined by CT parameters, by their number, amperage and, for example, for  U-220-2000-25U1 circuit breaker it may be as high as 30 seconds. Special algorithms of MIKO-21 with automatic stop of measurements allow avoidance of subjective mistakes and increase the number of measurements per one battery charge.

Four methods of resistance measurement start-up

There are four methods programmed in the instrument for resistance measurement start-up:

  • "Single-shot start-up", i.e., start-up by pressing START button located on the front panel of the instrument.  For implementing this method the test cable clamps are first firmly fastened on the tested object and only then the user starts up measurements.
  • "Start-up against circuit closing". In this case the measurement is started up after occurrence of electric contact between tested circuit and current or potential contacts of the test cable. Information obtained is displayed.  This mode is used together with needle-type press contact of the test cable and is intended for rapid testing of a large number of bolt joints.
  • "Regular start-up". Measurements are started up in the pre-specified time intervals.  This mode can be used for items rejecting.  The mode is used in the following cases:  when both hands are used for pressing the cable probe against the test points and there is nobody else to press the START button; for monitoring the changing resistance, e.g., during tuning; for rejecting the kit of resistors against limiting values of resistance specified in the instrument.
  • "Regular circuit". This mode is intended for regular automatic measurement start-up by the test circuit closing.  The mode is initiated by pressing the START button; the measurement is started against the test circuit closing, and the instrument gives a beep.  After getting the result the software automatically converts to the mode of waiting for the next circuit closing.
Archive of passport values of tested equipment

Company's archive of passport values of resistances (R transient) of circuit breaker contacts ensures automatic comparison between measured and passport values subject to circuit breaker grade indication;

Archive of the instrument contains passports of HV circuit breakers with indication of maximum and/or minimum permissible transient resistances of contacts, and passports for rejected resistors with indication of permissible values of the upper and lower thresholds of resistances.

The user can also add the required template.

Automatic comparison of measured and passport values of resistances

Availability of an in-built archive of passport values of eclectic resistances (main circuit of HV circuit breakers) facilitates automatic detection, and the device beeps if the results of measurements go beyond the permissible limits.

Interactive control

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 film 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's data base.

The device can be integrated into measuring systems under PC control of diagnostic laboratories and companies producing electric equipment.

Independent power supply, light weight and size
  • Availability of an energy-independent memory and a mode of "automatic storage of the results of measurements" considerably reduces the full time of the circuit breaker test owing to transfer of the data obtained from the substation area to the Company's office.
  • The above peculiarities ensure complete independence and high mobility of the instrument over the vast substation or workshop territory as you avoid troubles with a power cable, extension rod to the socket, and grounding.
Test cable of unique and ergonomic design

For convenience the standard kit includes only one type of a test package (Kit 3 includes two test cables with crocodile clips for high-voltage circuit breakers up to 110 kV).

Suitable cable or a set of cables can be selected from a large range of additional accessories:

  • Test cable, the instrument should be placed near a circuit breaker:

One set with spring-loaded contacts for measurements in busbars or in arc extinguish chambers.  Two other kits with crocodile clips (with current and potential wires) for circuit breakers of up to 10 kV, circuit breakers of up to 110 kV, and a part for circuit breakers of up to 220kV.

  • Test cable, the instrument should be placed in the lifter cradle:

Three kits that include cables with crocodile clips (with current and potential wires), a cable with a G-clamp (with current and potential wires). They differ in length and purpose, namely: for HV circuit breakers of up to 220kV, for HV circuit breakers of up to 330kV, some for 500kV, and for HV circuit breakers of up to 750kV.

  • Test cables for precision measurements and measurements on the circuit sections with the test current is applied to their end points.
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 bulk-oil circuit breaker, sec 10 ÷ 30
Time of measurement in Mode 3 on a bulk-oil circuit breaker with battery charge saving, sec 5 ÷ 15
Mains voltage ~90-264, 47-63 Hz = 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
In-built memory 1000 measurements
Number of tests (max. current, I=200A) more than 500
PC communication USB / USB Flash
Display Color graphic display,
multi-sensor, 480x272 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)
Warranty 3 years
Calibration period 3 years
Standard complete set
Photo Item, Index Application
Test block of MIKO-21 Test block of MIKO-21 СКБ139.00.00.000 Instrument and covering documents: Calibration Certificate, User's Manual, and a Log Book.
Set #2 Set #2 СКБ039.27.00.000 Current cables 2x2m (1.12 kg) with crocodile clips (jaw up to 50 mm) for circuit breakers of up to 10kV.
Mains cable Mains cable СКБ018.09.00.000 Mains cable 1 x 2 m. Weight 0.24 kg. For instrument connection to the power line. Temperature range -25°С ÷ +120°С. Rubber insulation.
Ground cable Ground cable СКБ010.01.00.000 Ground cable 1 x 1.75 m. Weight 0.07 kg. For instrument grounding. Terminated with a G-clamp and a lug for a screw. Rated current – 50А.
Shunt Shunt Type: 75ShSM M3 (75ШСМ М3). For checking MIKO-21 operability.
Safety devices Safety devices Type: VP2B-1V-2A (ВП2Б-1В-2А) (2 pcs). For the power source protection.
Tool bag Tool bag СКБ126.06.00.000 Convenient, robust, wear proof bag for transportation of cables, documentation and other accessories to MIKO-21.
Test cables, should the instrument be placed near the circuit breaker (on order)
Photo Item, Index Application
Set #1 Set #1 СКБ039.19.00.000
СКБ039.19.00.000-01
Current cables 2x1.5m (0.87 kg) with spring-loaded needle-type contacts for measurements in busbars or in arc extinguish chambers. Current range up to 200A.
Set #3 Set #3 СКБ039.25.00.000 Current cables 2x4.5m (3.79 kg) with a G-clamp (jaw up to 80 mm) for all the circuit breakers of up to 35kV, and for some circuit breakers of up to 110kV.
Set #4 Set #4 СКБ039.26.00.000 Current cables 2x6m (2.83 kg) with a G-clamp (jaw up to 80 mm) for all the circuit breakers of up to 110kV and some circuit breakers of up to 220kV.
Test cable Test cable СКБ39.24.00.000
СКБ39.24.00.000-01
СКБ39.24.00.000-02
Test cable with crocodile clips A25C (2 pcs) and a probe (2 pcs) for precision measurements and for measurements on the sections of the circuit to the end points of which the test current is applied.

  • To be used together with Set #2 - Length 2 m (СКБ39.24.00.000)
  • To be used together with Set #3 - Length 4.5 m (СКБ39.24.00.000-01)
  • To be used together with Set #4 - Length 6 m (СКБ39.24.00.000-02)
In particular, the cable can be used in case of measuring cables resistivity.


Test cables, should the instrument be placed in the lift cradle (on order)
Photo Item, Index Application
Set #5 Set #5 СКБ039.20.00.000
СКБ039.21.00.000

Test kit for circuit breakers of up to 220kV.

Current cable 1x1m (0.5 kg) with crocodile clips (jaw up to 50 mm).

Current cable 1x3m (1 kg) with a G-clamp (jaw up to 70 mm).
Set #6 Set #6 СКБ039.20.00.000
СКБ039.21.00.000

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

Current cable 1x1m (0.5 kg) with crocodile clips (jaw up to 50 mm).

Current cable 1x6m (2 kg) with a G-clamp (jaw up to 70 mm).
Set #7 Set #7 СКБ039.20.00.000
СКБ039.21.00.000-02

Test kit for circuit breakers of up to 750kV.

Current cable 1x1m (0.5 kg) with crocodile clips (jaw up to 50 mm).

Current cable 1x9m (4 kg) with a G-clamp (jaw up to 70 mm).
Additional accessories to the set (on order)
Photo Item, Index Application
Potential spring-loaded contact (2 pcs.) Potential spring-loaded contact (2 pcs.) СКБ023.21.00.000 Together with Sets ##3-7 for avoiding high transient resistances between an input pin and a cramp of the device.
Potential pin contact (2 pcs.) Potential pin contact (2 pcs.) СКБ023.22.00.000 Together with Sets ##3-7 for avoiding high transient resistances between an input pin and a cramp of the device.
Manipulating rod Manipulating rod СКБ110.41.00.000
СКБ110.41.00.000-01
СКБ110.41.00.000-02
The rod is designed to ensure convenient connection to contacts of a high-voltage item.

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.

Additional accessories (on order)
Photo Item, Index Application
USB 2.0 A-B Cable USB 2.0 A-B Cable USB cable 1 x 2m. For computer connection and data transfer. 
Safety Test Certificate IEC 61010-1:2001 on the MIKO-21
EMC Compatibility IEC 61326-1:2005 on the MIKO-21
MIKO-21 CE Conformity Certificate; valid until 02.10.2021
MIKO-21 is included in Russian Register of Innovative Products under #272, valid until 30.03.2019.
MIKO-21 is included in Russian State Register under #63180-16, valid until 17.02.2021.
MIKO-21 - EAC № RU Д-RU.ME97.B.00047; valid until 26.04.2020.
Testimonials about Microohmmeter MIKO-21
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.

Testimonials about Microohmmeter MIKO-21
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.

Testimonials about Microohmmeter MIKO-21
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.

Testimonials about Microohmmeter MIKO-21, PKV/U3.1
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.

Articles (1)
Modern MIKO milliohmmeters for measuring the transient resistances
Modern MIKO milliohmmeters for measuring the transient resistances
The market of instrumentation currently offers a large range of instruments for measuring the transient resistances of contacts that differ in the principle of operation, metrology characteristics, degree of automation, size, weight, and price.
Reviews (1)
Field tests of new instruments at Irkutsk Hydroelectric Power Station
Field tests of new instruments at Irkutsk Hydroelectric Power Station
At the end of July field tests of a new microhmmeter MIKO-21 were carried out on Irkutsk Hydroelectric Power Station High-Voltage Electric Equipment Site.

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