I am trying to make pressure/force sensors and measuring the corresponding signals on digital oscilloscope (DSO). But most of the time observing the interfering signals because of the wires/clips connecting my device to the DSO. It would be great if anybody can suggest to how to get rid of these interfering signals?
Dear colleague!
I want to note that we also often encounter such a problem. I am convinced that the interference that occurs at the input of the oscilloscope is connected not only by wires. These oscilloscopes have great sensitivity. To eliminate interference caused by wires, it is first necessary to use special coaxial cables designed for them. If you need to connect additional wires from the sensor to the oscilloscope in order to lengthen the line, you must use a shielded wire, and preferably coaxial.
After the implementation of these measures, if the interference does not disappear or does not decrease to a minimum, then the reasons must be sought elsewhere. Namely, in extraneous sources of interference. And in this case, you need to shield the sensor unit, use at least the usual C, PC, LS filters at the ends of the lines (cables).
Best regards, Islam.
Dear colleague!
I want to note that we also often encounter such a problem. I am convinced that the interference that occurs at the input of the oscilloscope is connected not only by wires. These oscilloscopes have great sensitivity. To eliminate interference caused by wires, it is first necessary to use special coaxial cables designed for them. If you need to connect additional wires from the sensor to the oscilloscope in order to lengthen the line, you must use a shielded wire, and preferably coaxial.
After the implementation of these measures, if the interference does not disappear or does not decrease to a minimum, then the reasons must be sought elsewhere. Namely, in extraneous sources of interference. And in this case, you need to shield the sensor unit, use at least the usual C, PC, LS filters at the ends of the lines (cables).
Best regards, Islam.
As U. Dreher mentioned, some pictures would help.
What is the model number of the sensors? Can you provide a URL to the datasheet? (I want to know the power requirements and the output impedance and signal level.)
As İslam İskandarov mentioned, using coax all the way from the sensors to the DSO may help. Avoid unshielded wires for carrying sensor signals. If you are using a typical 1x or 10x scope probe, the 10 or 15 cm ground lead can act like an antenna and pick up interference. Instead, connect the ground ring near the probe tip to the sensor's ground point, or use a plain coax.
Keep the sensor signal wires as far away as possible from high voltage or high current carrying wires, such as wires that go to motors or actuators.
If you try those things and still have problems, show us a picture of your scope traces that show the interference. It may be possible to reduce the interference at the source.
Dear Jan Kok! Thank you for supporting me! And many thanks to you for a more detailed explanation for our colleague, additional valuable advice that I think our respected colleague will help find the real reasons for the situation.
Best regards, Islam.
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