Author Archives: Olov
It is about 60 years since my father Gösta Lindholm with a friend developed and patented the first vibrometer of the type we kept working on and enhanced since then. US patent is a few years younger. The generation vibrometers we now work on is like the 8th generation and we still use the same moving coil velocity sensor, now in generation 3. Vibrometer design do have some similarities, the sensor generate a signal w/o power supply and in the first version it was directly driving the moving coil instrument that presented the data and in the newest version the signal is sent in to a Android based unit, currently a Samsung Note. We have for each version added functions that customers requested and we needed ourselves. Functions like bearing condition, filter and analysis tools have been added as technology made it possible.
The new generation ME22Droid http://www.vtab.se/products/vibrometers/me22-droid-vibrometer/?lang=en has besides vibration according to ISO standard, multiple bearing values L and g a peak list and also the possibility to store the data with a note. Information can also be sent using standard Android functions like SMS, Email, Bluetooth etc. Something that didn´t even exist in the imagination of Science Fiction writers 60 years ago. Then you wrote the numbers on paper and sent them with carrier pigeons, almost. It is also possible to play Angry Birds for free but it is not a requirement. If your Android unit is a phone you can also make calls with it but you can still have some practical use of it as a vibrometer. However you have to unplug the sensor when you answer the phone. Development continue and the ME22Droid will be possible to upgrade in several steps in the near future. If you choose to do so. Our aim is to give a possibility for the user to grow with the development of the MEDroid series. Closest to get finished are software enhancements that will give FFT analysis that can be stored, rule based expert analysis etc. ME22Droid level will also be enhanced so if someone like a different ISO standard than the standard 10816-1, large machine, soft foundation it can be done. If Kurtosis, Crest factor is a favourite it can be included, maybe in a “enhanced” mode or version not to clutter the basic and as we hope, easy to read display that is shown when starting. It is my sons Lars and Erik with their friend Caj that develop the software. So technology progress is moving on.
After 18 months work we presented a new Vibrometer at UH2012 trade fair in Gothenburg. It is a piece of software in a Android Phone. Currently Samsung Note is the only certified unit, Qualcom version not tested yet. Likely it is the first Android vibrometer and possibly the first vibrometer where you can play AngryBirds for free. We will develop the software further to include all ME series versions and functions and some more to come. It will be possible to upgrade as the versions are released.
Vibration measurement system at Vattenfall powerplant unit 3 and 4 Stenungsund have been updated after 34 years of use.
We have upgraded the system from a Vibroflex vintage 1978 with a push button channel selector to a 96 channel 01dB MVX system using XPR software including our software JVectorView to replace the sensor selector. JVectorView collect data from the OPC server option in the XPR 01dB system and present selected sensors in 1,4 or 6 polar plots with the 3 latest readings. JVectorview also include reference vector marker and process data display. The system enables various alarms and trending depending on operation status like power, temperature etc. including vector monitoring. JVectorView is also operated using WLAN in the control room on a 10″ PC thus enabling full control during plant operation. Same basic system is installed on a turbine with gearbox at EEM in Eskilstuna where we also have the possibility to remote analyse and control the system using internet. If you also have a Vibroflex or similar vintage device in your panel and or have a radial/axial turbine, a turbine with gearbox or another critical machine, then we can help you to upgrade or revise your monitoring. MVX/XPR system now also have options for on-line ESA for electrical motors including VFD using the same hardware.
01dB-Metravib is now ACOEM through a management buyout. We wish the new entity good progress.
Vibrationsteknik can this year 2012 celebrate 40 years of Good Vibrations. We will present some news during the year and you are welcome to visit UH2012 in Gothenburg at booth C02:42.
I got a used Prius 2005 hybrid some time ago and to make it more fun I have got a extra 82 Kg battery pack from Shanghai with the aim of going electric from work to home and back as a plug in hybrid.
I have so far had minimum 0.22 l/10 km consumption as the multi computer system in the vehicle only allow 48 km/h speed in electric only EV mode. Currently the BMS is on it´s way back from MI in the US and a upgrade. It is not so easy as you may think to make the multicell battery work as one unit and there are some 200 VDC 15 A and 48 VDC 50 A to play with taking care not to fry the OEM battery……
How do you evaluate vibration? My view is from a simplified European perspective so I try to follow a ISO standard. My favorite is the venerable ISO 10816-1 that is based on a limited shaky foundation from the 1950´s. To make it further easy to use as it was in the beforetime I look at all machines as large machines on weak foundation so it makes my need to remember numbers so limited so I can handle it.
So if a machines vibration measured according to the ISO is less than 2.8mm/s it is ok for new machine delivery and will live a long and happy life, I would likely accept 3.0-3.2 mm/s also as decimals in this area have limited value in my view.
When the machine reach formally 7.1 mm/s you should analyze and repair and get it down to around 3 mm/s depending on the machines life, cost for fix, life expectancy and time available, you may need to settle for something slightly worse.
If your machine reach 18mm/s you should avoid operation, investigation and repair is mandatory. Diesels, reciprocating compressors and hammer mills may be excluded.
Company record is currently 200mm/s on rotating machinery then you should tip toe out of the danger zone. Remember this my simplified view to make it easy, there are 10+ standards differentiating all kind of machines and a full CD when all vibration related standards are included. In my view comparing to some time proven limits give at least some guideline when machines need to be evaluated.
It started as a inverse loudspeaker long time ago. My father worked at a turbine maufacturer late 1940´s and needed a tool for the mechanics to evaluate the machines status on site after overhaul. He and a companion managed to make a moving coil velocity transducer and a instrument combination. Our family have worked with machine vibrations since that time. Efforts resulted in patents at the time, find here a US I found the other day: patent