I have a question out there for someone who is using Phase Analysis. We are currently using a CSI 2120 one channel analyzer. We are looking at a 2130 2 channel data collector with Phase Analysis. My question is, is it worth upgrading to the former? We sem to get good results with what we have would the newer collector give us more information that would help justify a 15k investment? What does this machine give me that the older one doesnt? Like to hear from someone who uses this equipment not salesman. Thanks.

Mike,

I use a 2120-2 2-channel analyzer. The two-channel enhanced capabilities are:
1) Operating Deflection Shape (ODS) test when amplitude ratio and phase are used to plot deflection at any frequency of interest.
2) Structural vibration test with impact (modal) hammer to identify natural frequencies, damping, and mode (deflection) shape.

Both capabilities deal with structural vibration problems. Making these measurements is only part of the story, since knowledge and skill for making structural modifications are essential to solve these problems.

Keep in mind that the 2120-1 can measure phase from a tachometer for balancing and basic ODS tests at 1xSS or 2xSS.

Besides the 15k$ extra for the instrument, you will spend more for sensors and cables, hammer, and training before you can do anything useful.

Walt
w_f_strong [at] msn [dot] com

Mike
advantages over the single channel box...cross channel phase with coherence is great for quick accurate checks of relative phase between accels...with ODS no requirement for keyphasor, photo tach or machine shutdown to apply tape...collect data including orbits from protection racks, have been doing this for several years on racks with no online link to plotting software with good results more than justifying the required research and set up time....you can also combine some readings allowing faster collection times

You can also take "relative" phase readings without a tach reference by using a 2120 single-channel box and a strobe light that has a TTL output (such as the CSI 444, a PK2 Pocket Strobe, or the Monarch Palm strobe). You just run the strobe output into the tach input on the 2120 and then tune the strobe to running speed and "freezing" any convenient reference point on the shaft (keyway usually) with a fixed point on the bearing housing, split line, etc. As long as you keep the reference marks aligned (very easy with the 444 strobe), you will get accurate relative phase measurments.

Personally, I would not upgrade to a 2-channel box just for cross-channel phase analysis. But 2-channel analysis takes you to the next level once you have the software (Advanced 2-Channel Analysis), force hammers (at least 2), adapters, cables, etc. that are needed. That will run you an additional $5k-$10k.

We have both 2120-2s and 2130-2s. All are 2 channel and we use the same accelerometers with both. There is a cable difference, but cables come with the analyzer. One thing to consider is the 2120s are going out of production and we are being told they will not be supported after 2009. Our plan is to trade in our 2120s by the 1st quarter of 2007.

Gary B

I agree with Rusty on two points; 1. the upgrade may not be worth it for just one thing (phase).
2. two-channel capability helps you go to the next level.
You should look at the total package that the two-channel analyzer will give you. You can check phase without a tach, plus you can check phase and coherence between equipment and the base for soft foot. You also can do all the other things mentioned (ODS, etc.). The most important feature for me is the one that captnb mentioned; simultaneous data collection. I take peakvue data on every bearing and it doesn't cost me any time whatsoever. It "piggybacks" with my horizontal point that I collect anyway. Gary has a good point about the cable/connector. The 2130 can use the eurofast connector, but it doesn't have to. It can still use the 25-pin connector like the 2120. Your problem will be that all of your 25-pin connectors are probably for single channel use. If you go with a dual-channel 2120, you'll need the 624A split-input adapter for simultaneous collection with one accel, and a 628A adapter for phase measurements and simultaneous data collection with two accels. Both of these adapters fit on the 25-pin connector and use a cable with a BNC connector. The 2130 doesn't require the 624A split-input adapter. You can use the yellow two-channel eurofast connector that comes with the 2130, or you can use the 628A adapter if you want to use BNC cables. The BNC cables are much easier to take on and off, but the eurofast connector is better around water (fourdrinier and press section).

David Eason

quote:

you can check phase and coherence between equipment and the base for soft foot

You know, I guess I've always known that at some level, but I've never done that.... would be very useful on 2-pole motors especially that have a "beat". I'll have to remember that. Just goes to show that no matter how experienced you are, or how much you think you know, there's always someone else who knows more. Thanks, David for mentioning it.

hanks to all those who have replied. This is what I needed to make a good decesion on our meter. Our meter works well and we seem to get analysis form our tech with this meter. He blieves he could get somewhat better data and go a little faster if he had this meter. Would it pick up one critical fault that the 2120 wouldnt? I am not sure , if it did it would pay for itself in a short time. I am in no hurry to buy but it is something I think I will look at by at least next year this time if not before. Thanks again for sharing.

I haven't actually had my hands on a 2130, but others here have. Personally, if money is not an issue, I'd go with the 2-channel 2130 as soon as I could. Running routes is a tough job... anything we can get our hands on that makes it easier, helps us do a better job. So I'd want the "latest-and-greatest"... but in my case, money IS an issue (it's always a little different when it comes out of your own pocket), so I'll just stumble along with my 2120 for now.

Mike, Cross channel phase with coherence is worth the money.
Good luck
/Adnan

Mike,

The 2130 has several bells and whistles that the 2120 doesn't have. If you don't need them it doesn't make any difference. I have some very slow speed gearboxes (.4 rpm output) that I take data on and with a 2120 you can only get down to a 20 Hz f-max, with the 2130 you can measure down to 1 Hz. If you have gearboxes it also has the pseudo-tach which makes it possible to order track or sync-time average with the trigger on the input shaft and get data on an intermediate shaft. Of course you can take 2 measurements at the same time on the same sensor with no limits on AP set too. If you go to CSI's web site they probably have more info.

MIke
WE use a 2120-2 and we have had the chance to use the 2130 as well.All the posts I see here are valid in the statements made.I found the new box to have lot of new features.Your posture when carrying the new unit is something I found to be a much needed improvement over the old boxes. I have a fused spine and found the 2120 did not agree with my condition.The 2130 on the other hand sits close to the body and reduces the strain on my back.The button configuration is also easier to use in the winter with your gloves on.Route collection time is shortened considerably.The display is veiwable in all lighting.The expert featuers are helpful and when we receive our new unit I am sure I will find many more things I like and some I will not like, but overall I like the new box.