The grounded junction is the most common type; it has a response time that falls between the exposed and isolated types and offers good thermoelement protection.
Isolated junctions have the slowest response time and are often employed when electrical conditions (such as ground loops) interfere with the thermocouple’s proper operation.
Exposed and sealed thermocouples have the fastest response time for a given diameter Naba-Pak®. On the downside, this type offers limited protection to the thermoelements; a reduced tip offers better service life while maintaining a fast response time.