Technical Library
To support and assist engineers in the test and measurement field we will feature a range of technical articles, useful tools and links on this page that can be used as reference material. In addition you will find technical details of the standard Kemo filter responses.
We also have a range of case studies that highlight some of the applications for Kemo products, this includes filters, impact hammers, accelerometers and low noise cables. Visit the APPLICATIONS page
What is Triboelectric Noise?
Many engineers are not aware of the phenomenon of triboelectric noise, this can cause siginificant noise issues in a measurement system. Triboelectric noise is ‘motion induced noise’ which can be caused in cables which are carrying a charge signal from devices such as piezoelectric sensors (for example accelerometers). As the cables flex due to movement the layers within the cable rub together causing electrostatic charge to build up, this charge must go somewhere and if the correct cable type is not used it can be added to the signal charge causing a noisy output. This issue is limited by using Low Noise Cables. This video demonstrates how low noise cable can minimise triboelectric noise.
Cable Length Calculator for IEPE Accelerometers
This is probably an issue many engineers have come across without understanding the reasons. When using an IEPE accelerometer which is most commonly powered by the source built into the DAQ system there is a potential issue with higher frequency cut off caused by the build up of cable capacitance in longer cables. This effectively creates a low pass filter.
To overcome this issue there is an easy solution which is to increase your IEPE signal source current supplied. Typically the standard source is 2mA or 4mA, however by increasing this to 6mA or even 8mA much longer cables can be used without any frequency degradation. If your DAQ is unable to offer this function, Kemo’ range of IEPE signal conditioning units and many of our electronic filter products also offer the option to increase IEPE signal conditioning.
DOWNLOAD a more detailed article.
🎥 Watch the video here to see how it affects and let us know what you think!
Explaining Electronic Filters
KEMO Article – An Introduction to Electronic Filters
- Article 1 – What is an Electronic Filter? Passive filter or Active Filter…..
- DOWNLOAD
KEMO Article – An Introduction to Electronic Filters
- Article 2 – What type of Electronic Filters can I use? High Pass, Low Pass…..
- DOWNLOAD
KEMO Article – An Introduction to Electronic Filters
- Article 3 – Specifying an Electronic Filter? Bessel, Butterworth, 4 Pole, 8 Pole…..
- DOWNLOAD
Kemo Article – An Introduction to Electronic Filters (Digital or Analog Filters)
The Advantages and Disadvantages of Digital Filters and Analog Filters, review the pros and cons of using real time analog filters or post digitised filters.
Calibration
Kemo Article – How to Calibrate Kemo Electronic Filters
A brief introduction into the critical parts of analog filter calibration beyond the obvious checks carried out by most calibration labs
DOWNLOAD Full Article
The Relationship between Acceleration, Velocity and Displacement
- The relationship between Acceleration, velocity and displacement – DOWNLOAD
Kemo Filter Response Details
Kemo Instruments Private Ltd standard filter responses, 01, 03,05,07,09 and 41 can be used with the full range of Kemo filter products, details of these filter responses can be seen below, download the datasheet for full filteramplitude and phase response.
Filter Response 01 – Anti Aliasing – Download Technical Detail
Filter Response 03 – 8 pole Butterworth – Download Technical Detail
Filter Response 05 – 4 pole Butterworth – Download Technical Detail
Filter Response 07 – 8 pole Bessel – Download Technical Detail
Filter Response 09 – 4 pole Bessel – Download Technical Detail
Filter Response 41 – General Purpose – Download Technical Detail
