Noise supression

Having problems ? let us know the details here
Post Reply

Noise supression

Post by alowi » Wed Apr 21, 2010 5:48 pm

Trying to use Picoscope 2203 with an Omega silicon bridge 0-100 millivolt output pressure transducer to capture and messure transient hydraulic pressures. The sensor has a dynamic range of 2 mHz (0.5 ms rise time). Does the software provide any high frequency filtering of noise up to 5 mV areater than 2 mHz?

Advanced User
Advanced User
Posts: 435
Joined: Thu Jun 07, 2007 10:53 am
Location: Cambridgeshire

Re: Noise supression

Post by PeterF » Wed Jun 16, 2010 3:38 pm

A silicon bridge pressure transducer will have a differential output and the 2203 has two single-ended inputs (Signal + 0V, on each channel). It would be best to use both channels, one for each output of the sensor and use "Channel Maths" to subtract one from the other. The resulting waveform will be the true output of the sensor.
The difficulty when using a single +10V/0V power supply for the sensor is that the two outputs of your strain gauge bridge will be at half-rail voltage, (+5V). You will not be able to select the highest sensitivity range of the 2203 to get good voltage resolution. (+/-50mV). Your strain gauge bridge probably has a rated input of +10V which will give the highest sensitivity. It is best to use a balanced (+/-) supply such that the voltages at the two differential outputs are near ground potential. If your single +10V/0V supply output is isolated from ground (floating) then it is possible to use a pair of equal (try 1K ohm) resistors in series across the output to generate a "Centre-Tap" to simulate the 0v connection of a +5V/0V/-5V power supply.
Your full bridge strain sensor will have a "+" and a "-" input terminal for it's power. Connect the +5V power lead to the sensor "+", connect the -5V lead to the sensor "-". Connect the junction of the two resistors (or the 0V of the supply) to the Ground connection of the 2203. The sensor will also have two output terminals, again probably marked "+" and "-". Connect the "+" to the Ch 1 input of the 2203. Connect the "-" to the Ch 2 input of the 2203.
When setting-up the the 2203, choose "Channel Maths" and "A-B".
Please contact again if you have any other questions.

Post Reply