Resistance measurement in inductive and non-inductive circuits in the range of 1 μOhm ÷ 10 kOhm The MIKO-8M(A) milliometer is developed to measure DC resistance in the range from 1 µOhm ÷ 10 kOhm for the current of up to 10А for: 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; Equalizing, current limiting and other resistors of high-voltage circuit bre­akers; Сables. The device provides a fully automated process of measuring the resistance of a high inductive load and compensation of thermoelectric power in the external circuit. Special measurement modes MIKO-8M (A) implements specialized measurement modes for various configurations of 10 objects (resistive object, inductive, voltage transformer, current transformer and power transformer, generator, motor, compensator, connection filter and magnet), taking into account their specific features, while The user can select a typical object from the proposed list or create his own object. The instrument automatically takes into account the configuration of the object for adjusting the measuring modes. Automatic mearsurement of 3-phase transformers 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 closed. SINGLE: the measurement starts upon the User's comman (by pressing the START button). PERIOD: the measurement starts automatically in pre-specified 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 current in the measure- ment 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 current that enables guaranteed saturation of the transformer magnetic system. Various auto calculations and non-volatile memory MIKO-8M (A) has a built-in archive of up to 200 measurements for viewing, copying or deleting data. And thanks to the possibility of choosing an object at the measurement stage, the results are presented more systematically. This facilitates interaction with the archive. The group of MIKO-7M(A), MIKO-8M(A) and MIKO-9(A) instruments has a number of automatic calculation functions: Auto δ calculation of Rphase between one another. Auto conversion of Rlinear to Rphase. Linear windings are Delta or Star / Wye (with no neutral) connected. Auto correction of R measured at t° to R at t°p. Auto δ calculation between Rcorrected and Rp. Auto calculation of t° by its R. Non-demountable estimation of the OLTC‘s (DRM test) OLTC in-place 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 instantaneous current drops. Test current firstly passes through the transformer winding and then through OLTC contacts at changing 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 opening of fault-free OLTCs. Milliohmmeter mode and DRM test complement each other and provide the User comprehensive informa- tion about the transformer state.


High level of protection and safety conformity 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 measuring current; emf of self-induction; overheat of the test block.. 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(A) 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. Touch screen, remote control and bluetooth data transfer 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. Variable instrument configuration None of the measuring cables is included in the standard equipment of the MIKO-8M(A) device.This allows the customer to choose exactly that kit. To select the User and the convenience of connecting to the object, measuring cables of different lengths and different types of clamps / fasteners are specially designed: Current cable 1 x 8.5 m with crocodile clips (jaw up to 80 mm); Current cable 1 x 8.5 m with a G-clamp (jaw up to 103 mm) for connection to transformer; Current cable 1 x 4 m with crocodile clips (jaw up to 25 mm) for resistance measurement of CT and VT windings; Current cable 1 x 3 m. Weight 0.5 kg. With 2 crocodile clips (jaw up to 25 mm) and 2 removable probes (length: 70 mm, plug: 3 mm) for transient resistance measurement of CT and VT contact joints and windings.

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).