LRT 640 - Low Resistance Tester
- Integration into an automatic system via PLC- and Ethernet-interface
- Manually testing of components in production and quality assurance
Features
- Resistance measurement at up to 4 measuring points at the same time
- Measuring range 1 up to 100 mW
- Contact test before each measurement
- Kelvin contact ratio metric measurement method including thermos voltage compensation
- PLC- and Ethernet- interface
- Short measurement duration approx. 50 ms / measuring point
Description
The instrument LRT 640 is used to measure small electric resistors in production lines, e. g. fuses.
The LRT 640 has a PLC-interface to be integrated into the sequencing of the production as well as an Ethernet-interface to acquire the production data.
The instrument measures up to 4 resistors of the same kind simultaneously.
A measurement can be started via PLC or pushing the start-button. Every activated measuring point is measured in the following way:
- Contact test: The resistance of the cable and the contact resistance of Rx are measured using a test current of approx. 100 mA.
- Zero measurement: During the idle state (no current) thermo-electric voltages may occur and affect the resistance test. Therefore a reference value is determined to correct the measurement results if necessary.
- Resistance test: The measurement current (0.5 A) through the DUT and the RREF is turned on and the resistance value is determined out of the ratio of the voltages (ratio metric measuring).
- The result is compared to the minimum and the maximum value and a “good”/”fail”-decision is made. Every measuring point has its own LED lamps to show the “good”/”fail”-result.