Help Choosing Scope

enirwin · Post by **enirwin** » Fri Jan 20, 2006 5:59 pm

I'm looking for a scope to evaluate pressure pulses from positive displacement pumps using a 5 V piezoelectric pressure transducer. The pumping frequency will range from 100-2000 Hz and I'll be interrested in harmonics up to 20 kHz. The expected amplitude of the pressure pulses can be anywhere from +/-1% to +/-50% of the mean pressure.

My main objective is to accurately capture the magnitude and frequency of the pressure pulses. Based on the Pico selection guide, I think I need a minimum bandwidth of 100 kHz and minimum sample rate of 100 kS/s. I'm considering the ADC-216 but am concerned that the bandwidth and sample rate might be a little too close to the minimum requirements. I've also looked at the PicoScope 3224 which has significantly higher bandwidth and sample rate but has 12 bit resolution as compared with 16 bit for the ADC-216.

As is probably evident by now, I'm not sure which is more important to my application, bandwidth and sample rate or resolution.

Any help will be appreciated.

Thanks.

Michael · Post by **Michael** » Mon Jan 23, 2006 11:47 am

Hello,

Thank you for your post.

If your output is Â±5v max, then a 12 bit scope will give you 2.44 millivolt steps. A 16 bit scope will give you 0.15 millivolt steps. The 12 bit scope gives you a very high resolution. How much of this resolution you use will depend on the output voltage of your transducer.

Also consider a scope that you can use for other applications. Our scopes are professional instruments that offer value for money. You may find a faster scope will offer more usage when this project has finished.

Best regards,
Michael