of thermocouples used at very high temperatures or in contamination-sensitive applications, the only suitable insulation may be vacuum or inert gas; the mechanical rigidity of the thermocouple wires is used to keep them separated. Reaction time The speed of response of the measurement system depends not only on the Data Acquisition system but also on the construction of the thermocouple sensor. When the temperature reading time is in several ms. The measuring tip of the thermocouple is insulated or not. However, the reading error in such extremely fast temperature measurements is caused by the insulation of the thermocouple tip. Even a cheap acquisition system such as an Arduino and Thermocouple Analog to Digital Converter or amplifier may have a response speed of several ms, but the design of the thermocouple will be important. Table of insulation materials Temperature ratings for insulations may vary based on what the overall thermocouple construction cable consists of. Note: T300 is a new high-temperature material that was recently approved by UL for 300 °C operating temperatures. Applications Thermocouples are suitable for measuring over a large temperature range, from −270 up to 3000 °C (for a short time, in inert atmosphere). Applications include temperature measurement for kilns, gas turbine exhaust, diesel engines, other industrial processes and fog machines. They are less suitable for applications where smaller temperature differences need to be measured with high accuracy, for example the range 0–100 °C with 0.1 °C accuracy. For such applications thermistors, silicon bandgap temperature sensors and resistance thermometers are more suitable. Steel industry Type B, S, R and K thermocouples are used extensively in the steel and iron industries to monitor temperatures and chemistry throughout the steel making process. Disposable, immersible, type S thermocouples are regularly used in the electric arc furnace process to accurately measure the temperature of steel before tapping. The cooling curve of a small steel sample can be analyzed and used to estimate the carbon content of molten steel. Gas appliance safety Many gas-fed heating appliances such as ovens and water heaters make use of a pilot flame to ignite the main gas burner when required. If the pilot flame goes out, unburned gas may be released, which is an explosion risk and a health hazard. To prevent this, some appliances use a thermocouple in a fail-safe circuit to sense when the pilot light is burning. The tip of the thermocouple is placed in