T&R DSM200 High Current Micro-Ohmmeter

T&R DSM200 High Current Micro-Ohmmeter

The T&R DSM200 High Current Micro-Ohmmeter is a high current device that is suitable for measuring very low resistances in a wide range of applications and is also suited to commissioning, maintenance, and production line environments. The DSM200 can safely measure contact resistances in circuit breakers, switch panels, isolators and busbar joints. Output currents up to 200A DC are provided and a 10A DC smoothed output can also be provided. This digital sampling micro-ohmmeter is simple to operate, with the user only required to switch the output on and set the test current. Selection of all ranges is fully automatic, and current, voltage and resistance are displayed simultaneously at all times on a large LCD display. The resistance is calculated from the test current and sense voltage and there is no need to set an exact test current to guarantee an accurate test result. To assist the user, all readings are held on the display when the output is switched off. Connecting the DSM200 to a PC running the optional DSMlog software adds data capture and reporting functions to the unit, allowing test results to be exported directly to Excel or saved to a file. All results are time stamped, and a comment may be added to each test. Data capture can be controlled from the PC, and the resistance of a test object can be monitored over a period of time. Alternatively, connecting a printer allows all of the test parameters to be printed automatically whenever the reading is held. For safety purposes the unit is protected by electronic over current and duty cycle trips on the output, thermal trips on the power components and fuses on the input and regulator. An earth terminal is also provided for connection to a local earth.

T and R DSM200 Features:

• 0-10A and 0-200A DC test current
• Maximum resistance of 17mΩ at 200A and 4Ω at 1A
• 0.1μΩ resolution
• mV, A, and μΩ displayed simultaneously
• Direct Ohms reading at any current
• Large back-lit liquid crystal display
• Thermal and over-current protection
• Isolated RS232 interface for printer or PC
• Triple supply voltage
• Microprocessor controlled
• High quality 3m lead set supplied as standard

Always ensure that power to the object under test is off and the object is earthed before testing. The DSM200 should also be earthed. With the output of the micro-ohmmeter off, connect the output cables to the busbar, ensuring that all joint resistances to be measured are included in the circuit. Connect the sense leads to the joint and switch the output of the DSM200 on. Increase the current to the desired level and switch the output off. The readings will be held on the display. Move the sense leads to the next joint (shown dotted on the diagram), and switch the output of the set on and off to measure the resistance of the joint. The results are printed out or logged to the PC if optional printer or DSMlog software is used.

For more information on T&R DSM200 High Current Micro-Ohmmeter talk to www.test-meter.co.uk