The conventional thermocouple is used with an outer protecting tube or thermowell to protect it from aggressive and corrosive process condition. This improves longevity of the thermocouple. However, response time is poor. To overcome above problem, has desi gned MI Thi ckwal l Thermocouple having thicker wall with relatively larger conductor diameters. This construction enable the user to inser t the thermocouple directly in the process without a protecting tube or thermowell, improving response time considerably.