Issues regarding the loop testing of temperature transmitters
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What are the specific steps for performing a loop test on a temperature transmitter?
Simply connect a resistance box to the temperature sensor and check whether the temperature displayed in the circuit is accurate.
A temperature transmitter is used to convert the resistance signal of a thermal resistor or the voltage signal of a thermocouple into a 4-20MA signal. What do you mean by performing a circuit test? Do you refer to the connection from the DCS to the temperature transmitter, from the detector to the temperature transmitter, or the entire circuit?
You mean the integrated temperature transmitter, right? The thermal resistor or thermocouple connected to the temperature transmitter has already been installed. If it’s connected properly, a hand controller can be used (one that uses the Heart protocol; those without this protocol can be operated using a signal generator). If no thermal resistor or thermocouple is connected to the end of the temperature transmitter, a resistance box should be added to the transmitter in order to generate a signal, and the resistance value should be adjusted according to PT100 or PT1000 standards (depending on the settings of the temperature transmitter).
The temperature transmitter circuit includes: a temperature sensing element (thermocouple or thermistor), the temperature transmitter unit itself, power supply and peripheral devices (such as safety barriers), terminals, and wiring. First, check whether the power supply and wiring are normal, then check the temperature sensing element, and finally check the temperature variation and settings.