RTD interfacing practice: Resistance temperature detectors (RTDs) are typically connected with other fixed resistors in which network for measurement linearization and sensitivity?

Introduction:RTDs provide a resistance that varies predictably with temperature. To convert this resistance change into a measurable voltage with good sensitivity and common-mode rejection, RTDs are commonly wired in bridge networks, often with 2-, 3-, or 4-wire compensation schemes. This question probes recognition of the standard connection method.

Given Data / Assumptions:

• Platinum RTD (e.g., PT100/PT1000) or similar.
• Desire for linearized, sensitive measurement.
• Use of precision resistors and instrumentation amplifier.

Concept / Approach:A Wheatstone bridge converts small resistance changes into differential voltages. In 3- or 4-wire RTD circuits, lead resistance effects are reduced or canceled. The bridge output is then amplified for digitization. While trimming (variable resistors) may be present, the core topology is a bridge network.

Step-by-Step Solution:

Verification / Alternative check:Textbook RTD circuits and vendor application notes consistently show 3- and 4-wire bridge connections to cancel lead resistance and improve accuracy.

Why Other Options Are Wrong:

• Pi configuration: Common in filters/impedance matching, not standard for RTD readout.
• And variable resistors: Too vague; trimming may be used but the defining network is a bridge.
• Filter-type circuit: Filtering may follow, but not the primary connection method.

Common Pitfalls:Ignoring lead resistance in 2-wire RTDs; failing to reference the bridge properly; omitting excitation current stability which affects self-heating and accuracy.

Final Answer:in a bridge configuration