Turbidimeter Issues

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ToxLabRat
ToxLabRat's picture
Turbidimeter Issues

All,

Just curious if anyone out there has some insight that they can share with me on this one.  We have a pretty new turbidity meter, which to the best of my knowledge has not had any issues since it was purchased about 2 years ago, not has it needed any type of maintenance, repair ro replacement parts.

Recently we have been having issues with getting the meter to standardize and stay that way.  Most of the standards are off by greater than 10% on the first few attempts at analysis, and in the majority of cases they are out  on the low side, and the higher the standard, the more the result is off from the target value. 

Just today, I cam over and it was not zeroed at all.  So I put the zero standard in the well and zeroed it without issues and then it was fine.  About 20 minutes later I come back and it has already gotten off again without anyone touching it durring that 20 minute period.  The only thing that changed was that I turned it off and then turned it back on.

I am curious (since there is not a great deal going on with a turbidity meter-light and detector) if it is the white light bulb needing to be replaced.  Especially since it seems as though the longer the meter has been on, the better its performance becomes and the better it is able to hit the standard at their target values within a 10% SD.

If anyone knows how often the light bulbs need to be replaced or anything at all about how frequently you should replace, cean, etc. any of the parts on this bench top meter, then I would appreciate it.  Oh and I have ordered new sample vials to make sure that it is not an issue with the vials being scratched on the outside causing the issues, however they have not yet come in.

Thanks
-Tox

Metalman 694
Metalman 694's picture
Just wanted to let you know

Just wanted to let you know that I have no experience with Turbidity meters, but I might be able to offer something that could help.

Maybe the memory is failing on the instrument?  I know some meters have a memory that keeps calibration data and items like that.  If the memory is failing then when you turn it off, the memory is wiped.  Are there any batteries that backup the memory?  They might need to be replaced.  Maybe that explains why the meter works great until you turn it off.

Again, I have no experience with them, but I hope this helps!

Metalman

ToxLabRat
ToxLabRat's picture
Thanks for the tip MetalMan. 

Thanks for the tip MetalMan.  This meter is very simple and does not store any data that I am aware of.  It is not even capable of being hooked up to a computer or printer to actually give data report print outs.  Instead all of the data has to be viewed and hand transcribed into a log book.

At any rate, I am pretty sure that the issue is either color interferences and/or light diffraction interferences, or possibly just a weak light.  It has never been been maintenanced since we purchased it and I think that this is something that we are going to need to have done.

If you run across any recommended routine maintenance and annual preventative maintenance recommendations for turbidity meters then I would greatly appreciate it, as I have had an extremely difficult time trying to find such information.

Thanks,

Tox

Metalman 694
Metalman 694's picture
Hi Tox,

Hi Tox,

What brand is the meter?  Maybe check their website to see if you can contact tech support or the site may have a manual you can download that can help you with routine maintenance.  If all else fails you can probably send it in to them and have them service it.  It could be that once a year a technician may have to service the meter as a PM measure.  Being that the meter hasn't been maintained properly for two years I'd say get it looked at by the manufacturer to ensure that the meter has the proper parts replaced and calibrated as well.

Hope this helps!

Metalman 

ToxLabRat
ToxLabRat's picture
It is an Orbecco.  I have

It is an Orbecco.  I have gone to their site as I have I read through the user's mannual that came with the meter, and on neither site can I find any information about recommended routine and/or preventative maintenance.  I had come to the same conclusion as you, I called the company last week to see if someone could provide me with the information that I was looking for and I was given a technical rep's email.  Hopefully he will email me back with some recommended maintenance routines.  I did talk to a college of mine who works in another lab and he said that they have their turbidity meter checked, maintenanced and calibrated once a year by the same guy that does the checking of their pipettes and scales, so I do think I will investigate as to whether the company that we use for those things can deal with this meter as well.  I will make sure to post any information that I get on it, seeing as how it seems to be hard to come by.  I guess those meters are just so simple that there probably is not a great deal of maintenance required, but still, I would imagine some amount of attention should be given to it once or twice a year.

Metalman 694
Metalman 694's picture
Hopefully the issues you are

Hopefully the issues you are having get cleared up soon!  Keep me posted and good luck!