how do i scale voltage to eu without the sound and vibration measurement suite?

[K.N]

Hi all, i am a new user to Labview and am currently doing my fyp using Labview to measure some sound signals and then manipulating them.

however, when i try to calibrate my microphone array, these are b&k 4957 ones, using the contacq & graph int clk.vi, i get a graph output (in Pa) of more than 7Pa at a measured sound level of 100dB (measured using an external Tenma sound level meter as a rough gauge), which is of course impossible. i understand from the boards that i should probably use the svl scale voltage to eu.vi, but i have neither the sound and vibration measurement suite nor the sound and vibration toolkit.

is there another way of converting the input signal so that i get accurate results?

i am using Labview 8.6, with a PXI-4498 board, a digital function generator and the mics to generate and record my signals.

Thanks very much for your help!

Kenneth Neo

[RavensFan]

Can you please explain some of the acronyms you used?

fyp

svl

eu

Also, please capitalize the word "I" and also the first letter of your sentences to make your posts easier to read.  (Otherwise they look like a long run-on sentence.)

If you have a voltage, and you need to convert it to another value, just do the math on it.

[K.N]

oh.. fyp = final year project.

I have no idea what SVS stands for.. the entire .vi is as follows, "SVS Scale Voltage to EU.vi" .EU would be engineering units here i suppose.

here is the scenario: Labview logs the sound pressures received by the microphone via converting the microphone voltages to pascals. my question is, how does labview do it? is there an equation that labview uses in the conversion? I understand that values acquired via a data acquisition device usually have a linear relationship with the voltage coming from the sensor; raw data comes in regular voltage units. Hence, i would need to scale the signal to the appropriate engineering units.

So how would i go about converting this voltage to pascals and finally dB? Or is there a direct conversion between voltage to dB? I cant find it anywhere on the web, and i dont have the Labview VI that does the conversion for me.

Hope you understand what im asking for now. Thanks!