We have a brand new plant wireless LAN system. Supposedly it can interface with any 802.11B or G device. We haven't put any vibration monitoring devices on it yet. We are thinking about starting on a simple/easy/cheap appliation - monitoring overall vibration on one particular machine that has has high 1x slowly increasing. Currently we monitor it daily just so we can plot a trend to show the rate of change. If we had a wireless sensor than we could use the wireless sensor for the trend data and get our spectra/TWF maybe once per week.

Any recommendations on simple/easy/cheap wireless accelerometer for the task?

Pete, I've looked into this a couple of times, and unless I am missing something, there is no wireless "accelerometer" that simply sends data to an existing analyzer/system. The problem (as I see it with my limited electrical/electronic knowledge) is the accelerometer output is analog, right? And our "devices" convert this signal to digital and present it as waveforms, spectra, and various "levels" (overall being one of many).

Wireless transmission of analog data seems to be a very big deal, whereas wireless transmission of digital data is almost trivial.

Everything I've seen involving "wireless vibration" monitoring is actually a system that does the A/D conversion and then transmitts the digital data wirelessly. There are a number of those, which is not what I want.

Is my understanding of the present state-of-the-art (??) correct?

The interesting thing is there are plenty of wireless pressure transmitters and flow transmitters. That was the type of thing we had in mind. Unfortunately it is not as common for vibration. Most of the wireless vibration setups such as honeywell, skf have a standard accelerometer hardwired to a box that provides wireless communication to the network. The box has the batteries and the ICP power supply and the wireless. I guess it would be tough to fit that all "into" an accelerometer and still make it easily mountable. I did find one like that which is a single box housing x/y accelerometers power supplies, wirelss etc.
http://www.pointsix.com/suppor...cuments/WIFI_VIB.pdf
Note it requires a large flat surface to mount that thing. Could perhaps mount on flat surface on top of the motor and it would give us the two horizontal directions (x and y built into the box). But the vendor said the output is simply digital 1 to 4096 and we need to do our own calibration (?). Originally designed simply to sense whether a machine was on or off... probably not what we want.

After looking just a little (not too much yet) the most promising seems to be Honeywell. Several accels hardwire to the box and the box transmits 802.11 b or g as we're told we need. I still haven't quite figured out what the software is that we will read it with (anyone know?). But we're definitely still interested in suggestions.

Wireless is by it's nature digital. That certainly meets our needs because we are not that ambitious (would be happy with an overall and if we get a spectrum and TWF with preselected sample rate, duration etc, that's a bonus). I can see you would not have as many options for tailoring the data collection as you would with a data collector reading an analogue signal directly from the accel. I'll bet there is some older radio technology to transmit an analogue signal if that's what you want. But most of the new stuff their selling is digital, won't give you that analogue singnal direclty unless you have a D/A which I haven't seen in any of the kits. And if you had a d/a the analogue output would of course be bandlimited based on original filter/sample rate.

This message has been edited. Last edited by: electricpete,

A system I have tested with the following:

1. 8 channels vibration (x,y each sensor), and 4 channels temp per node. Node is line or battery powered. 2500 Hz/150kCPM, 2048 point time waveform, 800 line spectrum.

This system can be configured to take temp, overall and spectrums as quickly as every 2 minutes with "on demand" mode. It communicates via mesh type wireless repeaters to a communication hub. The hub has broadband Verizon/Sprint/ATT card for bypassing plant LAN for internet based viewing of data with a web browser. If a hard wired connection is desired or needed, it has the option.

You can contact them on the website. They are working on oil and transformer oil monitoring as well along with other sensors.

http://waiteswireless.com/

Their pricing is MUCH lower than what is currently on the market.

The accleorometer has to have a power supply. Most wireles systemes require a power source be supplied to the accorometer, so the term "wireless" is kind of misleading.
We trialed a wireless system from Timken last year.
It consisted of a magnet mounted unit that housed the battery for power and the accelrometer. I think we had to mount a reciever that could pick up the signal from the accerometer and then have it hooked up to our lan system. We then monitored the data from our office. We use CSI software for our normal system. I am not sure if we had to load the Timken software into one of our computers or not.
The only contact information I have for them is for the Northwest region, but I am sure they could put you in contact with the rep for your area.
We were able to trial this for a couple of months. I don't think we paid for the trial, if we did it was a very minimal amount.
Hope this helps

Pete, Commtest are not far off this issue. They use Zig Bee not 802.11. Initial efforts are going into online units but I asked them at a recent vibration conference about unloading to a data collector and its development is not that far off. See attached.

The_Wireless_Revolution_VANZ_2009.pdf (2,509 KB, 64 downloads) Wireless Accelerometer Networks

You can try logal guys:
http://www.feddwireless.com/

I was using their system a long time ago and still in DOS OS. It'll do what you are asking for.

Try this,

Todd Gross
Summation Research
321-254-2580
grosst@summationresearch.com
751 N Drive, Melbourne,FL 32934

Before I left Florida I was beta testing a system for him that was like you are looking for.

El'Pete,

Based on the PointSix battery specification, it would only last about 15-days when sampling every 30-seconds! It sure would be nice to quickly mount a small self-contained and self-powered wireless vibration sensor and quickly get the desired overall level or spectrum for alarming and trending on you PC! I do not associate the word "wireless" with the words "simple" or "cheap". A single-wire vibration sensor (4-20 ma) connecting to a PLC might be simple/cheap and more reliable compared to the wireless products on the market at this time. What is the real cost and value of a wire (temporary or permanent) compared to wireless? If you find a suitable wireless solution for your application, then let us know.

Walt

Thanks everyone for those comments. Keep them coming.

Walt - What we have at our plant is brand new wireless network system. There is a perception that it should be cheap/easy to use it with field wireless devices and access the data through our normal (business) LAN. So far as I know we in the rotating equipment group are the pioneers to figure out exactly where the heck that easy path is. It may be there is an easy path out there but I just haven't stumbled onto the right people in our plant IT department and within our vendors to figure it out yet. There seem to be an endless variety out there but none that quite fits yet.

We did look at "point 6". They seemed very attractive initially. $290 per sensor. The sensor includes battery/2-axisaccelerometer and transmitter in a box. The box requires flat mounting surface. If you mounted the box flat on top of a vertical motor you would be sensing vibration in two perpendicular horizontal directions.. Accelerometer sensor communicates direct with the wireless network. Then you also need a box called a Point Manager ($250). It hooks to the LAN by ethernet connection (no wireless involved in the point manager) and it has the required software that facilitates accessing the data from the LAN. Then any LAN connected computer can get to any sensor knowing the address to read the present value of that point.

So far the device sounds good. But one problem you noted was battery life - I hadn't looked at that. Another problem is the output is a digital value 1 - 4096. Somehow related to acceleration (I'm not clear whether it's an overall or a peak). We're told it was originally designed for simply figuring out whether a machine is running or not. We were looking for a velocity overall. It seems a little too crude for us.

El'Pete,

Emerson/CSI has wireless transmitters for vibration. Worth a look, but not expected to be cheap.

Walt

Pete,

We use a system from Xerium Technologies that has the accels hardwired into the transmitters. The transmitters broadcast to a 801 g reciever. It uses the Maars software to give spectrum, waveform, and overall vibration levels. We have been using the system for over a year now. Maars has upgraded the software lately so it has become pretty stable.

Being low on the totem pole I don't have any specifics about price.

Our contact is Tim Rohrer (904) 535-7582.

Aubrey

Everyone on the planet (including us as AZIMA/DLI) wants to have this available.....the issues are:

Radios for 802.XXX eat amps....if you want data on any reasonable frequency (sample rate - how often does it report), then you will eat batteries.....

There is a big difference in sampling magnitude only versus timewave data that can be used and post processed for useful analysis......

Wish it were easier than it is.....

Non Vendor

I have mentioned this before - Try FEDD Wireless http://www.feddwireless.com

We set these battery operated units (pressure/flow (4-20mA)/Vibration) up localy and transmitted data using sat transmitter to US. Just requires transducers and receiver.

Regards

W

Thanks for all the comments. That has given us a lot of things to look at.

One thing we are focusing now is the ability to get the data into our Entek Emonitor database.

We noticed the Enwatch system can automatically feed data into the database. It is normally hardwired Ethernet output, but I think a simple adaptor can convert it to 802.1 wiress. Anyone have any experience with Enwatch?

Vendor -

Hey Pete

I can help you out. Shoot me an email.

Thanks

Greg

Thanks Greg. I would definitely like to communicate with you about this. Unfortunately I lost your email address. Can you post it?

Or else see my profile and send me an email.

I sent you an email - Thanks

Greg,

What is you company, and what is your wireless vibration product?

Walt

Pete,

Timken has a wireless system that I believe is a good fit for your application. Send me an email at don.nice@timken.com and I can email you some literature on them.