1. What is Wheatstone Bridge?

The Wheatstone bridge is a circuit used to measure unknown electrical resistance by balancing two legs of a bridge circuit. It's commonly used in sensor applications to measure small changes in resistance.

2. How Does the Calculator Work?

The calculator uses the Wheatstone bridge equation:

Where:

• \( R_x \) — Unknown sensor resistance (Ω)
• \( R1 \) — Known resistor 1 (Ω)
• \( R2 \) — Known resistor 2 (Ω)
• \( R3 \) — Known resistor 3 (Ω)

Explanation: The equation calculates the unknown resistance when the bridge is balanced (no current flows through the galvanometer).

3. Importance of Sensor Resistance Calculation

Details: Accurate resistance measurement is crucial for sensor applications like strain gauges, temperature sensors, and pressure sensors where small resistance changes need to be measured precisely.

4. Using the Calculator

Tips: Enter all known resistor values in ohms (Ω). All values must be positive numbers. The calculator will compute the unknown sensor resistance.

5. Frequently Asked Questions (FAQ)

Q1: What is the balanced condition of a Wheatstone bridge?
A: The bridge is balanced when the voltage between the two midpoints is zero, meaning R1/R2 = R3/Rx.

Q2: What are typical applications of Wheatstone bridges?
A: Commonly used in strain gauges, thermistors, light detectors, and pressure sensors where small resistance changes need precise measurement.

Q3: How accurate is this calculation?
A: The calculation is mathematically precise, but real-world accuracy depends on resistor precision and measurement equipment.

Q4: Can I use this for unbalanced bridge calculations?
A: No, this calculator assumes the bridge is balanced. Different equations are needed for unbalanced bridges.

Q5: What if my sensor resistance is very small?
A: For very small resistances, consider using a Kelvin bridge (a modified Wheatstone bridge) for better accuracy.