Discussion Category:  Centrifuge

speed testing

is there any specific to test a speed in ultra high speed centrifuge?

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Asked by

acemedical
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avatar placemarkReply by
dpkleessr

Yes there is.  It requires a frequency test meter with the appropriate clip leads in order to attach to the test points on the control board.  The cover of the centrifuge needs to be removed in order to get access therefore there are safety issues too in that you can get around some technically lethal voltages so great care must be taken if you don't know what you are doing.  There is NO optical way in order to verify the speed in this type or ANY other ultracentrifuge.

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acemedical

thank you so much, is there a specific place I can order the test meter  and specific model I can use for this task?

 

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dpkleessr

I really don't know what to tell you about the frequency meter anymore as I retired over 3 1/2 years ago.  Mine was provided by Beckman Coulter and it had the proper input characteristics to not load the circuitry down.  I will have to try to find out where the test point is again because I just don't remember anymore.  Why are you concerned about the speed readout to begin with?  I performed operational qualifications on those centrifuges as long as they were around before I retired and never had ANY speed accuracy issues because everything is digital.  I'll see what I can find out on the meter and test points from former colleagues but that won't be possible for a few days.

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acemedical

I have a new job to calibrate those ultrahigh speed centrifuges, and I never done calibration for them

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dpkleessr

Just a point of information, there is absolutely no adjustment possible as to the speed calibration of an Optimal Max.  It literally is what it is.  The same applies to time and temperature, too.  Their is an internal temperature calibration procedure that can be performed with the appropriate service codes but otherwise there are no actual adjustments.  If you are expected to take temperature readings there is also a very specific way in which that is to be done in order to get accurate testing.

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acemedical

I know all of that, we need to verify if the speed of Ultrahigh centrifuge is correct. I found frequency counter meter and hopefully it will work in our application

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dpkleessr

OK. I will attempt to find out the correct test points and get back to you but don't expect anything until after the 4th.

Don

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acemedical

thank you Don, I was told that on a centrifuge supposed to be posts and the frequency meter is to connect to those posts, then measure the frequency and multiply by 60 and that will be it's speed, does it make any sense?

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dpkleessr

Not necessarily. It really depends on the centrifuge model.  The Optimal Max is a direct readout whereas older models had multipliers.  As your questions are dusting off parts of my brain that haven't thought about this subject in literally years, I recall that the test points on the Max are not posts or connectors at all.  There are just solder pads on the board that you hold the probe against VERY CAREFULLY!  If you slip off of the pad you will likely cause a drive or speed diagnostic of some kind.  That is why you cannot afford any mistakes doing the speed check.

Don

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acemedical

there are different models of centrifuges we have to work on, what was your job before?

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