HI , Everyone,
Please check attached file. I tested the NI USB-TC01 with a type S thermocouple in a furnace. The furnace temperature was set to increas to 1300 oC. But during the furnace heating up over 1100 oC (shown on the furnace controller), the reading of NI USB-TC01 started to drop down to 800 oC even the real temperature was kept increasing. I used another thermometer to read from the S thermocouple. The thermometer's reading showed the same temperature as that from the furnace controller.
Also I noticed the reading of NI USB-TC01 kept dropping from room temperature to 0 oC before the furnace started running.
When the NI USB-TC01 connecting with a type B thermocouple, there is no such problems. Is there any special care needed to Type S thermocouple using NI USB-TC01?