Comparison of milliohmmeters MIKO-7 and MIKO-8 with the new modifications

Dear specialists, we inform you that two new versions of MIKO-7M and MIKO-8M milliohmmeters will be manufactured in the second quarter of 2018. Production of previous versions of MIKO-7 и MIKO-8 will be discontinued.

Similar to their predecessors (MIKO-7 and MIKO-8) new devices MIKO-7M and MIKO-8M have been designed for measuring:

• DC electric resistance of windings of power and measurement transformers, windings of electric motors, generators, linear compensators and windings of other high-inductance equipment;
• Transient electric resistance of selector contacts of OLTC devices,  of earthing devices, disconnecting switches and other detachable and non-detachable contacts;
• DC  electric resistance of resistors, wires, buses and other inductance-free circuits; 
• Transient electric resistance of selector contacts through an open OLTC tank of PC-3 and PC-4 types, which allows the electric resistance of power transformer windings to be eliminated from the results of measurements thus providing more accurate information on the technical state of those contacts.

Moreover, MIKO-8M similarly to MIKO-8 allows recording the oscillogramms of contacts switching over of a fast-acting OLTC device both without its opening, by connecting to transformer terminals, and with its opening, by direct connection to closing switch contacts (DRM-test method).

New versions of milliohmmeters will have a number of basically new performances that will make them superior to their previous versions:

	MIKO-8M	instrument is removed from the production	MIKO-7M	instrument was removed from production in mid-2018	instrument was removed from production in mid-2018
		MIKO-8		MIKO-7 with advance software	MIKO-7 with basic software
Measuring range	10 µOhm ÷ 10 kOhm	10 µOhm ÷ 10 kOhm	10 µOhm ÷ 2 kOhm	10 µOhm ÷ 1 kOhm	10 µOhm ÷ 1 kOhm
Current rate range	0.001 ÷ 10A	0.0014 ÷ 10А	0.01 ÷ 10A	0.0014 ÷ 10А	0.0014 ÷ 10А
Non-volatile memory	up to 1000 measurements	up to 100 measurements	up to 200  measurements	up to 100 measurements
Display	sensor, color, graphical TFT display (5")	color, graphical TFT display (5.7")	monochrome graphic display, 128х64	four-rowed monochrome digital display	four-rowed monochrome digital display
New user interface		-		-	-
Power supply an in-built battery	on request, modification  MIKO-8MA		on request, modification MIKO-7MA
Weight with battery, kg	4.0	-	4.0	-	-
Weight without battery, kg	2.7	3.2	2.7	3.2	3.2
IP rating in operating state	IP40	IP20	IP40	IP20	IP20
Специализированные режимы измерения для различных объектов, учитывающие их специфические особенности	10 objects		5 objects
Automatic setting of measuring current
Manual setting of measuring current
Специальный режим измерения в безиндуктивных цепях (3 способа запуска процесса измерения)
Время измерения в режиме для безиндуктивных цепей	2 - 4 sec	20 sec	2 - 4 sec	20 sec	20 sec
In-place checking and express diagnostics of OLTC condition at any weather conditions without removing the contactor tank cover
The amplitude resolution of the current	12 bit	8 bit	-	-	-
Automation of the measurement process

Next year we plan production of one more milliohmmeter, MIKO-9 that is also designed for measuring the DC electric resistance in inductance and inductance-free circuits, but the range will be 10 mkOhm ÷ 30 kOhm on the current  of up to 10A.  MIKO-9 has a number of other differences from new modifications and their analogues. For more details see Ref.

All the instruments are currently under tests and undergo pilot operation for being entered into the RF State Registrar of Measurement Instruments. Their production is scheduled for the second quarter of 2018. Orders for purchasing are accepted.