A sensor system comprising: - an exchangeable cartridge (CR, 110,210) with an examination region in which a sample can be provided and with a first and a second contact region (C1, C2, C3) where it can be contacted; - a reader (RD, 150) with an accommodation space for the cartridge (CR, 110,210) and with a sensor unit (155, 156) for making measurements in the examination region of the cartridge (CR, 110,210); - at least one contact element (CE, 111,211) by which the cartridge (CR, 110, 210) is supported in the accommodation space and which comprises or touches the first contact region (C1, C2), wherein there exists a "high-resistance" cross section (a-a) through the contact element (CE, 111,211) for which the thermal resistance is higher than the thermal resistance at any other "low-resistance" cross section (b-b) that (i) cuts through the body of the cartridge (CR, 110, 210), (ii) comprises the examination region, and (iii) separates the first contact region (C1, C2) from the second contact region, and wherein the thermal resistance at any low-resistance cross section (b-b) is less than 50%, preferably less than 10 %, more preferably less than 3 % of the thermal resistance at the high-resistance cross section (a-a); characterized in that the at least one contact element (CE, 111, 211) comprises a leg (111, 211) extending from the cartridge (CR, 110,210) or the reader, wherein the leg (111, 211) comprises a zone of lower thermal conductivity achieved by the inclusion of a thermally insulating material, wherein said high-resistance cross section (a-a) passes through said zone. - an exchangeable cartridge (CR, 110,210) with an examination region in which a sample can be provided and with a first and a second contact region (C1, C2, C3) where it can be contacted; - a reader (RD, 150) with an accommodation space for the cartridge (CR, 110,210) and with a sensor unit (155, 156) for making measurements in the examination region of the cartridge (CR, 110,210); - at least one contact element (CE, 111,211) by which the cartridge (CR, 110, 210) is supported in the accommodation space and which comprises or touches the first contact region (C1, C2), wherein there exists a "high-resistance" cross section (a-a) through the contact element (CE, 111,211) for which the thermal resistance is higher than the thermal resistance at any other "low-resistance" cross section (b-b) that (i) cuts through the body of the cartridge (CR, 110, 210), (ii) comprises the examination region, and (iii) separates the first contact region (C1, C2) from the second contact region, and wherein the thermal resistance at any low-resistance cross section (b-b) is less than 50%, preferably less than 10 %, more preferably less than 3 % of the thermal resistance at the high-resistance cross section (a-a); characterized in that the at least one contact element (CE, 111, 211) comprises a leg (111, 211) extending from the cartridge (CR, 110,210) or the reader, wherein the leg (111, 211) comprises a zone of lower thermal conductivity achieved by the inclusion of a thermally insulating material, wherein said high-resistance cross section (a-a) passes through said zone. (i) cuts through the body of the cartridge (CR, 110, 210), (ii) comprises the examination region, and (iii) separates the first contact region (C1, C2) from the second contact