HCL2922 (10A) High Current (DC) Winding Resistance Meter

Description: 
The HCL2922 High Current Winding Resistance Meter is special designed for low resistance measurement in high inductance circuit. Main application is power transformer. HCL2922 has high accuracy, and based on four point measuring technology, which enable the system has high performance on resistance measurement.
HCL2922 meets the requirement of IEC 61010 & IEC 61326. The quality is reliable.

Feature: 
The device equip high performance thermal printer. The data print every half minute.
The RS-232 connector enable the system connect with computer directly.
High charging power to guarantee the measurement of high capacitance power transformer. The device can saturation charging in very short time.
The temperature raise of the device can be handled by the inter software automatically.
Safety. The device has special designed safety discharge circuit to guarantee the safety of the operators and device itself.
Exterior appearance of this device has been improved many time, and form this classical creation. 

Test Cells:
Mode and Range:HCL2922(10), 10A (10A, 5A, 1A, 10mA, <10mA…) 
Parameters:
Input current: 10A, 5A, 1A, 100mA, < 10mA
Measuring range: 0mΩ ~ 0.6Ω (10A)
                             2mΩ～3Ω    (5A)
                            10mΩ～20Ω  (1A)
                            100mΩ～200Ω  (100mA)
                            200Ω～20kΩ    (<10 mA)
Resolution: 0.2%±2μΩ
Operating temperature: 0℃～40℃
Relative humidity: ≤90%
Power supply: AC220V±10%, 50Hz±1Hz
Dimension: 395x240x250mm
Weight: 10kg
Warranty: one year

Accessory: 
Three core power line - Test line(black) - Test line(red) - Grounding line(with clamp) - Shunt - Insurance tube [Left to right sequency]

Question:
Is there some rule or guideline when to use a different current injection for certain resistance to be measured?
Answer:
For LV side of transformer DC resistance test-start with high current until stable reeading; For HV side of transformer DC resistance test-start withsmall current until stable reeading. You can refer to below range of current: 0-0.6Ω 10A, 2mΩ-3Ω 5A, 10mΩ-20Ω 1A, 100mΩ-200Ω 100mA, 200Ω-20kΩ＜4mA