To reduce the loading effect, an instrument must possess a high input impedance. This is because the input impedance of an instrument determines the amount of current that flows into the instrument when connected to a source. A high input impedance means that the instrument draws very little current from the source, minimizing the loading effect.


The loading effect occurs when the impedance of the instrument connected to a source is significantly lower than the source impedance. In such cases, the instrument draws a significant amount of current from the source, causing a decrease in the source voltage and affecting the accuracy of the measurements.


Having a high input impedance is crucial for accurate measurements in many electrical and electronic applications. Here are some reasons why a high input impedance is desirable:

1. Minimizes Current Flow: A high input impedance means that the instrument draws very little current from the source. This minimizes the loading effect and ensures that the source voltage remains relatively unaffected.

2. Prevents Signal Distortion: When an instrument has a low input impedance, it acts as a significant load on the source, altering the voltage levels. This can distort the signals being measured and introduce errors in the readings. A high input impedance avoids such signal distortion.

3. Preserves Signal Integrity: High input impedance ensures that the instrument does not significantly alter the voltage or current being measured. It allows the instrument to 'listen' to the source without interfering with or altering the signal, preserving its integrity.

4. Wide Range of Applications: Instruments with high input impedance can be used in a wide range of applications, including voltage measurements, impedance measurements, signal analysis, and data acquisition. This versatility makes them suitable for various scenarios where accurate and non-intrusive measurements are required.


In summary, an instrument with a high input impedance is essential to reduce the loading effect. It minimizes the current flow from the source, prevents signal distortion, preserves signal integrity, and enables accurate measurements. By ensuring that the instrument does not significantly alter the source voltage or current, a high input impedance allows for precise and non-intrusive measurements in a variety of electrical and electronic applications.