Limitations of Ammeters & Oscilloscopes for Measuring Current & Voltage

[dagg3r]

hi can somebody just breiefly list me some points about ammeters and how they are inaccurate and why when measuring in current in nano

and also about the cathode ray oscilloscope how when we plot voltages it is inaccurate and why.

thanks just basically want to know the limitations of these equipments

 

[hotvette]

This might help.

http://www.allaboutcircuits.com/vol_1/chpt_8/4.html

 

[quicknote]

There are several limitations of using ammeters and oscilloscopes for measuring current and voltage. Some of these include:

1. Limited range: Ammeters and oscilloscopes have a limited range of measurement, meaning that they can only accurately measure within a certain range of values. This can be a problem when measuring very small currents or high voltages.

2. Inaccurate readings: Ammeters and oscilloscopes can be affected by external factors such as magnetic fields, which can cause inaccuracies in readings. This is especially true for measuring small currents in the nano range, where even the slightest interference can affect the accuracy of the measurement.

3. Loading effect: When an ammeter is connected to a circuit, it can affect the behavior of the circuit and cause inaccuracies in the measurement. This is known as the loading effect, and it can be a significant limitation when measuring small currents.

4. Resistance of the circuit: The resistance of the circuit can also affect the accuracy of ammeter readings. In circuits with high resistance, the ammeter may not be able to accurately measure the current passing through it.

5. Time-varying signals: Oscilloscopes are designed to measure time-varying signals, but they may not be accurate when measuring signals with very high frequencies or very short durations. This is because the response time of the oscilloscope may not be fast enough to capture the entire signal.

6. Calibration: Both ammeters and oscilloscopes need to be calibrated regularly to ensure accurate readings. If they are not calibrated properly, it can lead to significant errors in measurements.

7. Human error: As with any scientific equipment, human error can also play a role in inaccurate readings. Incorrectly setting up the equipment or misinterpreting the readings can lead to incorrect measurements.

Overall, while ammeters and oscilloscopes are useful tools for measuring current and voltage, they do have limitations that need to be taken into consideration. It is important to understand these limitations and use the equipment properly to ensure accurate measurements.