The best high-temperature thermocouple is type S
The very best thermocouple for constant high-fire applications is a Type S platinum thermocouple with an alumina sheath.
This is normally only recommended for the most extreme conditions (like firing crystalline glazes) because of its expense - or if the value or precision of your work is such that you do not want to risk thermocouple drift.
You can special order a DynaTrol or Genesis with Type S thermocouples. They are not available for the One-Touch™ control.
The Type S thermocouples that we provide have a 5/16" OD alumina sheath.
They are ungrounded.
There are two lengths: 120mm (4.75") and 160mm (6.3")
Termination is in a ceramic terminal block.
- Type S thermocouples are composed of a positive leg which is 90% platinum and 10% Rhodium, and a negative leg which is 100% platinum.
- It is usable from 32°F to 2700°F. (0°C to 1480°C).
- It has a different EMF output than Type K thermocouples (meaning the same temperature will produce different voltages to the control which must then be interpreted differently).
- That different scale requires both a simple hardware configuration change and a software change to take effect so it can not be done inadvertently.
- At temperatures used in pottery kilns (even the highest 2350°F) these thermocouples can last for a very long time (as long as they are not mechanically broken).
Retrofitting a control with Type K Thermocouples
- This is not a retrofittable option on DynaTrols used before Jan 1, 2006.
- On the newer 700 DynaTrol boards or Genesis control it is possible to switch from Type K to Type S with a programming change and a jumper change.
- You MUST also change the thermocouple extension wire from Type K wire to Type S wire.
Important Note when replacing a control when using a Type S Thermocouple
- If you have a Type S thermocouple or are retrofitting an older kiln with a Type S thermocouple the control must be configured for use with Type S thermocouples. If not the kiln could seriously overfire and meltdown. See this for more information...