Hi,
I am working with an accelerometer posted below. In industry are there any instruments that can record the measurements of a voltage for 12 seconds and display the powr spectrum of it. I tried using oscilliscope in fft mode but it is displaying only instantanious values. I am looking for an instrument that can record and display power spectrum and also have an option to control the rate of sampling as well. Do we have spectrum analyzers that can record the waveform for 12 seconds ?
http://www.pcb.com/products.aspx?m=601a02

 

Can your scope do secondary math on the FFT channel ? Like averaging or
RMS ?

Or does it have a PC utility where you can write a script to process
spectrum display channel ?

Regards, Dana.

 

Hi,
I am working with an accelerometer posted below. In industry are there any instruments that can record the measurements of a voltage for 12 seconds and display the powr spectrum of it. I tried using oscilloscope in fft mode but it is displaying only instantaneous values. I am looking for an instrument that can record and display power spectrum and also have an option to control the rate of sampling as well. Do we have spectrum analyzers that can record the waveform for 12 seconds ?
http://www.pcb.com/products.aspx?m=601a02

Yeah, there are plenty of instruments that will do what you are asking. Were you planning to directly come off the accelerometer or were you going to use a charge amplifier like those typically used with an accelerometer of that type?

What I believe you want is a data logger which are available from various manufacturers. As it is your accelerometer is +/- 10 G with a sensitivity of 500 mV/G so if you are not signal conditioning using a charge amplifier you want a data logger which can read the accelerometer output directly. You can go with a simple starter kit from a company like DATAQ or Measurment Computing for simple data acquisition or you can go more expensive. Even the simple inexpensive units afford basic software as well as software development kits if you want to write your own. Really depends on what you want to spend. I have used the DATAQ acquisition units with accelerometers. Here is a very crude and basic example:



I can record, playback and set the sample rate.

Ron

 

Yes it is called a Dynamic Signal Analyzer, like the following

http://www.testequipmentdepot.com/usedequipment/hewlettpackard/spectrumanalyzers/3562a.htm

 

Yeah, there are plenty of instruments that will do what you are asking. Were you planning to directly come off the accelerometer or were you going to use a charge amplifier like those typically used with an accelerometer of that type?

What I believe you want is a data logger which are available from various manufacturers. As it is your accelerometer is +/- 10 G with a sensitivity of 500 mV/G so if you are not signal conditioning using a charge amplifier you want a data logger which can read the accelerometer output directly. You can go with a simple starter kit from a company like DATAQ or Measurment Computing for simple data acquisition or you can go more expensive. Even the simple inexpensive units afford basic software as well as software development kits if you want to write your own. Really depends on what you want to spend. I have used the DATAQ acquisition units with accelerometers. Here is a very crude and basic example:

View attachment 163003

I can record, playback and set the sample rate.

Ron

I am using a signal conditioner as shown below:
http://www.pcb.com/Products.aspx?m=482C15

and i am also amplifying the signal coming from the output of signal conditioner to range in between 0 to 3.3V using an ic741 Amplifier.

 

OK, your sensor has a range of +/- 10 G
Your sensor Sensitivity: (±20%) 500 mV/g (51 mV/(m/s²)) which is +/- 20% so unless you have the sensor calibrated and get a calibration report with it you are +/- 20%.

Not sure why you are using a 741 to amplify as the signal conditioner you have offers gain of 1, 10 and 100 and your sensor has a pretty strong sensitivity out. 1.0 G would be 500 mV and a full scale of 10 G would be 5 Volts. I guess the use of the 741 allows you to scale the accelerometer so fo example -10 G to 10 G = 0 to 3.3 Volts?

Anyway, I would go with a data acquisition type device allowing you to record your data using a fast enough sample rate and scale your data as well as add user annotation and having a differential input. Much like I suggested earlier.

Ron

 

Using A to D converters you can record the digital value and then convert the values to FFT and with the help you great coding techniques you may store the values in JSON format or using CSV format but to create the spectrum analytics there is some software available or you can also design your own spectrum analysis using an online dashboard tools.

 

Hi,
I am working with an accelerometer posted below. In industry are there any instruments that can record the measurements of a voltage for 12 seconds and display the powr spectrum of it. I tried using oscilliscope in fft mode but it is displaying only instantanious values. I am looking for an instrument that can record and display power spectrum and also have an option to control the rate of sampling as well. Do we have spectrum analyzers that can record the waveform for 12 seconds ?

What time resolution/frequencies are we talking about?

Generally, a LeCroy scope can do that, and actually this is one area (like mechanical tesing using transducers and accelerometers) where a lot of the early (1998-2001) white cabinet WaveRunner LT scopes are still in use today.

What model exactly depends on the frequencies involved and the budget but there are suitable scopes from the old 9300 Series from the early '90s to the current product portfolio.