What do Generic-2-/3-Wire RTD and Generic 4-Wire RTD mean, and what are the differences between them?

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RTD thermoresistors, two-wire, three-wire, four-wire. Two-wire system has large errors; it is used the least ； Both three-wire and four-wire systems can eliminate lead errors, with the three-wire system being the most commonly used.

Generic, class, type, genus. wire, electric wire, cable. RTD, thermal resistance signal. In short, they are thermal resistors with two-wire, three-wire, or four-wire configurations. Check for the specific differences on your own; it’s similar to what was said on the third floor – the four-wire system is better than the three-wire system, which in turn is better than the two-wire system. The three-wire system is the most commonly used. The bridge balance principle compensates for wire resistance, thereby reducing measurement errors in thermoresistive signals.

1. The fundamental differences among the three wiring methods for Pt100 platinum resistors: The two-wire and three-wire methods use the bridge method for measurement, and what is provided in the end is the relationship between the temperature value and the analog output value. In the four-wire system, there is no bridge; it relies solely on a constant current source for transmission and a voltmeter for measurement, with the measured resistance value being provided as the result. 2. The impact of the three wiring methods for Pt100 thermistors on measurement accuracy: The resistance of the connection wires and the contact resistance can have a significant effect on the temperature measurement accuracy of Pt100 platinum resistors; the three-wire or four-wire wiring methods for these resistors can effectively eliminate such effects. The detection devices connected to thermal resistors (display instruments, DCS inputs, etc.) all have four terminals: I+, I-, V+, V-. Among them, I+ and I- are used to provide a constant current to the Pt100 platinum resistor, while V+ and V- are used to monitor the voltage changes of the thermistor, thereby detecting temperature changes sequentially. Please refer to the following images: http://yunrun.com.cn/upload/201603/26/201603261751044598.png http://yunrun.com.cn/upload/201603/26/201603261751230613.png http://yunrun.com.cn/upload/201603/26/201603261751570856.png Two-wire Pt100 wiring, Three-wire Pt100 wiring, Four-wire Pt100 wiring. yunrun.com.cn/tech/192.html ①In the four-wire Pt100 configuration, 2 wires are drawn from each end of the thermal resistor (a total of 4 wires). The circuit for voltage measurement is separated from the circuit for measuring resistance, which results in high measurement accuracy; however, more wires are required. ②The Pt100 three-wire system involves using three wires for the Pt100 platinum resistor; in the wiring of Pt100, the reference point of the current circuit and the reference point of the voltage measurement circuit are the same wire (that is, the I-terminal and V-terminal of the measuring device are shorted together). It offers slightly better precision; three-wire platinum resistors are commonly used in industrial settings. ③The two-wire configuration for Pt100 means that two wires are used to connect the Pt100 platinum resistor; in this setup, the current circuit and the voltage measurement circuit are combined into one (that is, the I- terminal and V- terminal of the measuring device are shorted together, as are the I+ terminal and V+ terminal). The measurement accuracy is poor.