RF cable can be customized for other specifications

Brand AVX TPSE226M035R0125 Low impedance tantalum capacitor AVX 22

Murata muRATA winding inductance original authentic assured purchase

The three wiring methods of Pt100 thermal resistance differ in their principles and impact on measurement accuracy. Understanding these differences is essential for ensuring accurate temperature readings in industrial and scientific applications. The two-wire system and the three-wire system both operate using a bridge method, where the relationship between the temperature value and the analog output is determined. However, the four-wire system works differently. Instead of relying on a bridge, it uses a constant current source to send current through the sensor and measures the voltage drop across it, allowing for a more precise calculation of resistance. One of the main challenges in measuring with Pt100 sensors is the effect of wire resistance and contact resistance. These factors can significantly affect the accuracy of temperature readings, especially when long cables are used. To mitigate this, the three-wire and four-wire configurations are commonly employed. These systems effectively eliminate the influence of lead resistance by separating the current and voltage measurement circuits. In most modern test equipment—such as temperature controllers or PLC inputs—the Pt100 resistor is connected using four terminals: I+ (current positive), I- (current negative), V+ (voltage positive), and V- (voltage negative). The I+ and I- terminals supply a constant current to the sensor, while the V+ and V- terminals monitor the voltage change, which is then used to calculate the resistance and, subsequently, the temperature. Here's a breakdown of the different wiring methods: (1) **Four-Wire System**: This method uses four separate wires, connecting both ends of the Pt100 sensor. It separates the current loop from the voltage measurement loop, resulting in high accuracy. However, it requires more wiring and is typically used in high-precision applications. (2) **Three-Wire System**: In this configuration, three wires are used. The current loop and voltage measurement loop share one common wire, which helps reduce the impact of lead resistance. This setup offers slightly better accuracy than the two-wire system and is often used in many industrial applications. (3) **Two-Wire System**: This is the simplest method, but also the least accurate. Both the current and voltage measurements are combined into a single loop, making it highly susceptible to errors caused by wire resistance. This method is generally not recommended for precise temperature measurements. For a visual comparison of the wiring methods, refer to the image below: