VIbration monitoring story from my ancient past. Back in my younger days around 1977 I was a seagoing Junior Engineer on a very large tanker ship. The company decided to experiment with using vibration testing for condition monitoring on all the various bits of plant around the engine. This involved a portable unit around the size of a 1960s transitor radio which had a meter on it and (istr) a four postion filter switch that could used to select the vibration frequency band.
I got the job of going round all the dozens of rotary pumps, fans and motors in the engine room and fitting a special connector on each piece of plant to let the vibration pick-up make a good solid mechanical conection to the casing of the pump or motor .
The second part of the job was to take and record readings for each of the various machines which could be used as a known good for future diagnostics.
I wasn't on that ship long enough to know if the project did anything useful but at the time I wasn't that impressed.
Looking back I can now see it was probably beyond the capabilities of the old analogue equipment.
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)
Very cool Andy! One of my coworkers sons is a professional vibration tech for an oil and gas company. I guess he uses various tech for determining what condition equipment is in.
I ordered a ADXL335 and a Meas micro sense piezo sensor over Christmas and waiting for it to come in. Also grabbed a generic Uscope.
Looking forward to posting up some captures of signals caught with both style sensors.
Very cool Andy! One of my coworkers sons is a professional vibration tech for an oil and gas company. I guess he uses various tech for determining what condition equipment is in.
I ordered a ADXL335 and a Meas micro sense piezo sensor over Christmas and waiting for it to come in. Also grabbed a generic Uscope.
Looking forward to posting up some captures of signals caught with both style sensors.
Much as I think my little DSO201 Nano is great I am not sure good it will be for NVH. I tried mine yesterday with the the electronic stethoscope on an injector and the results were OK looking at a single injector but too much detail was lost looking at a parade of injectors. Although this was at looking at higher frequencies (2,500 to 100,00 hz) than typical drive line NVH problems.
Also the DSO Nano lacks any FFT (Fast Fourier Transform) display.
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)
Richey.brown wrote: I have only used it to identify a noisy pulley once and it seemed to work fine the only problem is the customer didn't have the money to pay for the job.So I never did the before and after process to see the end results but you will definitely be surprised on how accurate the little sensor is. This video is where I got the idea from
I use knock sensors, bolt them a magnet. I use the round ones a little over an inch in diameter. I also have a Rotkee sensor. I like that as well and has a clamp built in.
I noticed my Toyota has a vibration at 2000 RPM. I was going to get an accelerometer and a small data logger from Adafruit but they were out of the logger. I found an app for my phone that has FFT so I downloaded it. I placed it on the console and started recording. I looked for the biggest spike and at idle it was around 25 Hz. I checked power steering fluid and it was down. I added fluid and checked the vibrations at idle again. The peak vibration shifted to around 45 Hz. This did not address the vibration at 2000 RPM but I thought it was interesting and somewhat useful. A good baseline is probably key to making good use of vibration data.
