Thermocouple blocking protection
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What is the burnout protection of thermocouples and thermal resistors? Please describe the working principle in detail, and whether the disconnection is a function of the transmitter, thermocouple, or resistor.
When the instrument finds that the detection equipment is disconnected, the output will be prohibited and specific characters will be displayed on the panel. The user will be reminded to pay attention to the disconnection protection.
I know that the value indicated by the commonly used thermal instrument will be a meaningless value and fluctuate when the connected detection equipment such as a thermocouple resistor is internally broken. At this time, the upper or lower limit alarm control output set in the instrument may have an error signal output. Therefore, when the instrument finds that the detection equipment is disconnected, the output will be prohibited and specific characters will be displayed on the panel. The user is reminded to pay attention to the protection against couple failure.
Burnout protection: When it is detected that the thermocouple or thermal resistance measurement loop is open, the conversion output is a preset value. Working principle: By detecting the input loop resistance to determine whether there is an open circuit, a burnout can be determined. Is burnout a function of thermocouples and resistors? It is a function that can only be possessed by control system input modules such as transmitters, converters, alarm setting periods, secondary meters, and DCS.
This is actually achieved by using a secondary instrument such as a transmitter to detect the voltage at the line end after the current in the loop changes in resistance beyond the limit.
Support the very thin couple protection mentioned on the 4th floor: When it is detected that the thermocouple or thermal resistance measurement loop is open, that is, when the loop resistance is infinite, a preset value or symbol is converted and output. Working principle: By detecting the input loop resistance to determine whether there is an open circuit, a burnout can be determined. Is burnout a function of thermocouples and resistors? It is a function that can only be possessed by control system input modules such as transmitters, converters, alarm setting periods, secondary meters, and DCS.
The disconnection function means that after the thermal resistor or thermocouple is disconnected, the secondary instrument switches to a predetermined protection state to prevent parking or other accidents. It is a protective measure.