The AEMC 6250 10A Micro Ohmmeter is a rugged, low resistance tester designed for both plant maintenance and field use. Accurate results within 0.05% are obtained using a four-lead Kelvin method. Resistance measurements are automatically calculated, taking into account the measurement value, ambient temperature, metal type and metal temperature co-efficient. Metal temperature can be manually entered by the operator or directly measured with al RTD temperature probe.

The AEMC 6250 is designed to conduct tests on both resistive and inductive material, with operator selection directly from the front panel with three test modes available, resistive (instantaneous test), inductive (continuous test), and auto (repetitive test). Up to 1500 measurements can be stored and printed directly to a printer of from a PC.

The Megger DLRO10HD features 0.1 micro-ohm resolution, 0.2 per cent basic accuracy and a dedicated mode for use with inductive loads making it suitable for applications such as checking welded joint quality, verifying winding resistance in large motors and transformers, performance of lightning protection bonds and aircraft structures. High or low output power selection is available for condition diagnosis with a maximum output of 10A for 60 seconds. The unit is also protected from inadvertent connection to a line or UPS up to 600V. Power is supplied via the rechargeable battery or line power supply enabling continuous operation, even with a flat battery.

Test Modes

• Normal mode, the test is initiated by pressing the ‘test’ button. The instrument verifies continuity of all four connections, and then applies the test current in both forward and reverse directions before displaying the result.
• Automatic mode, the test starts as soon as the probes make contact with the item under test.
• Automatic unidirectional mode is the same as automatic mode, but the test current is applied in one direction only. This reduces the testing time, but thermal EMFs from contact between dissimilar metals may reduce the accuracy of the results.
• Continuous mode makes repeated measurements at three-second intervals on the same sample.
• Inductive mode is, as the name suggests, optimised for tests on motors, transformers and other inductive loads, supplying a full 10A for 60 up to seconds

Brief Specs:

• Temperature Coefficient – < 0.01% per ^oC, from 5 ^oC to 40 ^oC
• Display size/type Main 5 digit + 2 x 5 digit secondary displays
• Battery type 6 V, 7Ah sealed lead acid
• Voltage input range 90 – 264 V, 50-60 Hz
• Battery life 1000 Auto (3 sec) tests
• Auto power down 300s
• Test leads DH4 lead set included
• Safety rating In accordance with IEC61010-1
• Operating temperature and humidity -10 °C to +50 °C <90% RH

The Megger DLRO10X 10A micro ohmmeter is able measure resistance from 0.1 µΩ to 2000 Ω by automatically selecting the test current range up to 10A dc. Measurements are made with forward and reverse currents to cancel the effects of any standing voltages across the test sample. The measurements are then displayed along with the average value within 3 seconds to a basic accuracy of 0.2%. High and low pass limits are able to be set by the operator enabling simple go-no-go testing.

To enhance safety and ease of use the DLRO10x utilises a pair of duplex handspikes with one of the probes fitted with LED’s. These duplicate indicators on the instrument display indicating that all four contacts have been made, the presence of a high voltage across the load and the presence of current flow while a load is discharging.  The Megger DLRO10x has a large, backlit LCD display and features a RS232 communications port for results to be downloaded in real time. Up to 700 sets of results complete with notes may be stored within DLRO10X that can be downloaded later to a PC.

Brief Specs:

• Small, lightweight and portable – can be used in tight places, reduces the need for extra long leads and two person operation.
• Four terminal resistance method shows the true resistance of the item under test.
• Bright LCD display is easily visible under all lighting conditions and reduces human error.
• Automatically applies forward and reverse currents which cancel out any standing voltages across the sample under test.
• Checks for undue noise during measurement, reducing the possibility of recording the incorrect result.
• Automatically detects continuity in P and C circuits, preventing erroneously high reading to be taken due to high resistance contact.
• Battery module has a battery condition indicator allowing the user to check the state of spare batteries without connecting to the instrument.RS232 connector on the DLRO 10X allows downloading of results in real time or stored for later retrieval.

The Megger DLRO200 200A micro ohmmeter measures resistances between 0.1 μΩ and 1 Ω at high currents, can provide test currents from 10 amps up to 200 amps subject to the load resistance and supply voltage and uses a four terminal measurement technique to cancel the resistance of the test leads from the measurement. The high current capability and compact design make the DLRO200 suitable for testing circuit breaker contacts, switch contacts, busbar joints or other applications where high current is needed.

A large liquid crystal display provides all the information needed to perform a test with all test parameters and measurement results displayed. 300 sets of results may be stored in the DLRO200’s on board memory for later download to a PC or may be outputed directly to a printer via the RS232 port, notes can be added to any stored result by using the on board alphanumeric keypad. As well as adding notes to stored results, the alphanumeric keypad allows you to set the test current directly by typing in the value required. The DLRO200 will check the continuity of the test circuit, and will quickly ramp the test current up to the desired level. The keyboard is also used to set upper and lower limits for the result and to prevent the use of excessive currents by setting an upper limit to the allowable test current.

Brief Specs:

Measurement modes

 

Continuous mode Provided for users who wish to monitor a resistance over a period of time, the instrument will pass a current continuously and measure the resulting voltage at 2 second intervals until the test button is pressed to stop the test or the test circuit is interrupted.

Normal mode The test current will ramp up to the desired level, hold for 2 seconds and then ramp down. The whole process takes approximately 10 seconds.

Auto mode The test lamp will flash to show that the DLRO200 is ready to carry out a test. As soon as the potential leads are connected a test will start. To repeat a test simply break contact with the voltage probes and remake contact.