oliveandme
Newbie level 4
Hello,
Here is an experiment I'd like to do. I would like some advice on anything I might be doing wrong.
Aim of experiment:
To determine the dB level of a signal being generated on the Signal Generator. This dB level signal will be played through a calibrated speaker to a microphone on a CSR8675 Dev board to determine the energy level of different dB level signals. Based on a code I have written on CSR, I'll collect the FFT data and calculate the signal magnitude to determine the energy.
Hardware I have access to:
A PE/IEPE Signal conditioner, Signal Generator (SG), An Oscilloscope (OSc)
I'm going to explain this experiment in 2 steps for easy understanding.
First half of experiment:
I'll connect the output of the Signal Generator (SG) to the input of the Oscilloscope (Osc). I'm debating whether a Signal conditioner should be used as an intermediate between the SG and OSc. Once the SG is connected to the OSc, I'll generate a Sinusoidal Signal (1 kHz) of Peak-Peak Voltage of 1.0 V on the Signal generator. I'll observe the aforementioned signal on the Osc. The Signal on the Osc should have a Peak-Peak Voltage.
Using the above data that I have, I want to determine what is the dB level of the signal being generated on Signal generator . Does the 1.0 Vpp correspond to a 40 dB or a 60 dB .
This is the part where I am confused. I read this post which covers a similar topic.
https://www.edaboard.com/showthread.php?t=235708
based on which I decided a couple of options would be an appropriate way to calculate the dB level.
I'm not sure if either of my assumptions are wrong or both are wrong.
1. dB = 20 log10 (Voltage 1 / Voltage 2)
Voltage 1 = Vpp on the Oscilloscope ; Voltage 2 = Vpp on the Signal Generator.
2. dB = 20*log_10(Voltage 1/ V ref)
Voltage 1 = Vpp on the Signal Generator. Vref = Reference voltage of the Signal generator (I'm not sure what this reference voltage might be)
So are both my assumptions wrong ? How can I calculate the dB level ?
The final goal is to have this signal from the SG resemble a real world 40/60/80/100 dB signal and determine the energy level.
The questions that I have are
a. Is my experiment setup correct ?
b. Is the signal conditioner necessary ?
c. Which of my calculations (1 or 2 ) are correct to calculate the dB level ? Or are both wrong ?
Any help would be appreciated.
Here is an experiment I'd like to do. I would like some advice on anything I might be doing wrong.
Aim of experiment:
To determine the dB level of a signal being generated on the Signal Generator. This dB level signal will be played through a calibrated speaker to a microphone on a CSR8675 Dev board to determine the energy level of different dB level signals. Based on a code I have written on CSR, I'll collect the FFT data and calculate the signal magnitude to determine the energy.
Hardware I have access to:
A PE/IEPE Signal conditioner, Signal Generator (SG), An Oscilloscope (OSc)
I'm going to explain this experiment in 2 steps for easy understanding.
First half of experiment:
I'll connect the output of the Signal Generator (SG) to the input of the Oscilloscope (Osc). I'm debating whether a Signal conditioner should be used as an intermediate between the SG and OSc. Once the SG is connected to the OSc, I'll generate a Sinusoidal Signal (1 kHz) of Peak-Peak Voltage of 1.0 V on the Signal generator. I'll observe the aforementioned signal on the Osc. The Signal on the Osc should have a Peak-Peak Voltage.
Using the above data that I have, I want to determine what is the dB level of the signal being generated on Signal generator . Does the 1.0 Vpp correspond to a 40 dB or a 60 dB .
This is the part where I am confused. I read this post which covers a similar topic.
https://www.edaboard.com/showthread.php?t=235708
based on which I decided a couple of options would be an appropriate way to calculate the dB level.
I'm not sure if either of my assumptions are wrong or both are wrong.
1. dB = 20 log10 (Voltage 1 / Voltage 2)
Voltage 1 = Vpp on the Oscilloscope ; Voltage 2 = Vpp on the Signal Generator.
2. dB = 20*log_10(Voltage 1/ V ref)
Voltage 1 = Vpp on the Signal Generator. Vref = Reference voltage of the Signal generator (I'm not sure what this reference voltage might be)
So are both my assumptions wrong ? How can I calculate the dB level ?
The final goal is to have this signal from the SG resemble a real world 40/60/80/100 dB signal and determine the energy level.
The questions that I have are
a. Is my experiment setup correct ?
b. Is the signal conditioner necessary ?
c. Which of my calculations (1 or 2 ) are correct to calculate the dB level ? Or are both wrong ?
Any help would be appreciated.