Transmille 8500 - Manual (Page 5)

8500 LOW THERMAL SCANNER
OPERATION MANUAL
Transmille Ltd. Page 4
8500 Low Thermal Scanner
The model 8500 Low Thermal Scanner provides a low thermal 4 terminal switching
system making it ideal for 4 wire resistance measurements in resistance
thermometry and for resistance comparisons.
The use of ultra low thermal 4mm terminals make connecting the scanner to UUT's
easy, allowing the measurement system to be quickly re-configured. With the output
from the scanner located on the rear panel connections can be routed efficiently,
providing a neat and simple cabling solution.
Applications include scanning of both electronic and standard reference cells,
standard resistance comparisons measurements and PRT probe measurements.
Special care has taken in the scanner designed to minimize thermal generated EMF
voltages. By reducing internal self heating to almost zero by using a very low power
circuit, even the power supply is external, using latching relays which only need a
single pulse of power to set and using gold platted de-oxgenated copper terminals
thermal voltages have been reduced to less than 150nV.
Control is from the Serial RS232 or USB interface (using converter) or via the front
panel control buttons. LED indicators show the selected channel. The internal
firmware ensures that two channels can never be selected at the same and that the
switching is break before make.