Low-Pass Filter Questions

Low-Pass Filter Questions

NOTE: THIS HAS BEEN SOLVED IN VERSION 4.4.0.29 BY APPLYING THE FILTER TO BOTH LOAD AND POSITION CHANNELS.

In the "Load Cells" menu, the Low-Pass Filter can be activated or deactivated. Some common values are 3rd order 5Hz cutoff and 3rd order 20Hz cutoff.
The lower the cutoff, the more data will be filtered from the load cell's signal.
This can be used to minimize noise in a lab near a road where cars drive by or if there are other noisy machines in the room such as air conditioning.

During IMPACT or SINUSOID testing, the low-pass filter should be deactivated. Both these test types require reading rapidly changing data, and it is possible that the low-pass filter will interpret some of the high frequency data as noise.
During SINUSOID analysis in Mach-1 Analysis, the "Sinusoid" fit will also output the Phase (deg). This value indicate the delay between force and displacement and is an important data point for some viscoelastic samples. If a sinusoid test is run with the low-pass filter activated, the Phase (deg) will be incorrect. The sinusoid test should be run without the filter if the Phase (deg) result is important.


    • Related Articles

    • Questions and Answers regarding the Hayes model (1972)

      What is the Hayes model (1972)? The Hayes model is a mathematical model developed for indentation tests of articular cartilage. The articular cartilage is modeled as an infinite elastic layer of a certain thickness bonded to a rigid half space. This ...

    • Questions and Answers regarding Spherical Indentation of Cartilage

      Is there a suggested Poisson's ratio to use when analyzing indentations? If an indentation is performed in 1 second or less, it can normally be considered "instantaneous" and a Poisson's ratio of 0.5 should be used (i.e. the liquid inside the sample ...

    • Load Cell Handling

      It is important to be knowledgeable about your load cell before handling such a sensitive device. Please view the following video for basic tips on handling: https://youtu.be/ah3yxFmwBas Another particularity of single-axis load cells is that the ...

    • Camera related errors (Error: 5003, Error: -200279)

      The camera integration into Mach-1 Motion is very intensive on the PC. If Mach-1 Motion is not able to run smoothly and starts losing data, an error will appear. To minimize the likelihood of camera errors, try the following suggestions: ALWAYS save ...