Generally use Lake Shore for monitoring and control, a bit pricey but good.

InterNET SRL seem to be their representative in Romania

Piata Lahovari nr. 5A, et. 4, ap. 10, sector 1

RO - 010464, Bucharest, ROMANIA

http://www.inter-net.ro/

1) If you are looking for simple measurement upto -196deg C then 4- wire PT100 will work.You can log the data using LabVIEW based program using NI-DAQ 9219.

2)If high decimal accuracy is required then you should use Lake Shore as mentioned above.You can log the data using LabVIEW based program using GPIB card/ RS232 installed in PC.

The resistivity of a pure copper wire is nearly linear in your region.

Does Klaus Schaefer still exist? are they in business?