Abstract A temperature-variable high accuracy (TVHAR) 10 kΩ resistor has been developed at the National Instituteof Metrological Research, (INRIM), in order to transfer the traceability to high accuracy multifunctioninstruments used in the accredited calibration laboratories. The TVHAR consists of ten 100 kΩ nominalvalue resistors inserted in a copper block and connected in a parallel configuration. The thermal stabilityof the copper block is obtained with a temperature controller. In this paper details of the development ofthe TVHAR and of its thermal behaviour are reported . From preliminary results its relative short-timestability (2h) is on the order of a few parts in 10 −8 , a negligible temperature coefficient around 23 Canda power coefficient on the order of -4 −10 6 /W. c 2009 Polish Academy of Sciences. All rights reserved 1. Introduction Some electrical instruments like digital multimeters (DMMs) and multifunctioncalibrators (MFCs), widely used as standardsfor precision measurements,are calibratedby means of a particular process called “artifact calibration”, which requires only asmall number of reference standards: 1Ω and10kΩresistance standards and a 10 V dcvoltage standard [1 3]. The possibility to transport from the primary laboratory (NMI)to the secondary laboratories only a voltage reference and standard resistors instead ofdelicate instruments like calibrators increases the accuracy of the traceability transferand makes the calibration easier and technically convenient.We developed a prototype of a temperature controlled resistor for using it asstandard in all those precision measurements performed in a laboratory at a temperaturedifferent from 23