Recertify Weights

[Cliff]

When we purchase new weights they come with a certificate ensuring their accuracy. The certificate expires 1 year after receipt.

Does anyone recertify their weights?

[Michelle Mullikin]

Each year we return our weights and have them recertified. We made this part of our master equipment list and track the dates. We use the recertified weights to annually check all weights used throughout the blood center. Our certified weight were purchased from Ohaus and we use Troemner company to recertify each year. Address: 201 Wolf Drive ~ P.O. Box 87 ~ Thorofare, NJ 08086-0087 ~ Phone 856-686-1600 ~ Fax: 856-686-1601 ~ www.troemner.com ~ e-mail: troemner@troemner.com

Our facility was sited during an FDA inspection several years ago for not complying with manufacturers recommendation for maintaining annual calibration of weights as outlined in the manufactures certificate.

[David Saikin]

I did not care to purchase weights for my phlebotomy area . . . too expensive. What I did was go to the maintenance department and get a heavy chunk of metal. I weighed it 20X and used the average for my standard weight to validate my volume of blood collected. The FDA does not have any problems with this; their only recommendation was that I revalidate the weight of the weight annually. I do this by weighing it 20X with documentation.

[ChrisH]

We recertify our weights also.

[luhubert]

We don't draw donors and use weights only to calibrate the scales we use for therapeutic phlebotomies. We aren't FDA inspected. Do you think we need to recertify our weights?

[ChrisH]

We are a transfusion service only and we recertify. But we can get FDA in .

[Cliff]

Thanks for the valuable input.

I will be presenting this topic tomorrow at an Operations meeting.

I will propose we purchase weights identical to what we have now so we can send the others out to be calibrated, then rotate annually.

[Wade Atkins]

We have a contract service use their certified weights to calibrate ur scales and balances eevery six months. They also certify our weights for daily qc.

[Cliff]

We decided to recertify our existing weights.

Obviously this will not be a small project. We first need to determine what weights we have, then figure if this fits what we really need.

Next we'll need to order a duplicate set of weights so we will have a working set while the duplicate set is being calibrated.

Then we need to enter them all in our equipment database and ensure they are properly maintained.

Doesn't it seem that we blood bankers make a lot out of small issues?

[pmalone@cbccts.org]

Weights used in the collection/creation of blood components have to be traceable to an NIST standard. We have a master set of weights that is sent out each October for certification. All other weights used in our facility are measured against the master set annually.

[Cliff]

Weights used in the collection/creation of blood components have to be traceable to an NIST standard. We have a master set of weights that is sent out each October for certification. All other weights used in our facility are measured against the master set annually.

So, using this technique you are essentially certifying your own weights, traceable to your NIST traceable. That's an interesting option, especially for us, we have a lot of weights, many custom.

[Jane]

I loved David's idea of checking the weight on a calibrated scale. Our Mettler balance is calibrated and checked yearly by the company and I think I will use it to verify our weight each year. I am in the process of validating a new blood collection mixer. Do you all think that checking its weight measurement by weighing 3 bags of different weights on it and our Mettler balance say 10 times each and averaging these and calculating any difference is sufficient?? The company gives very little guidance except to say that a known weight should weigh within +/- 1 gram. I thought this same process could be repeated yearly as a calibration check. Then we will also check the calibration daily with our weight. As part of the validation, the techs will also each do a checkoff to make sure they understand the procedure and all the bells & whistles like the clamp and alarms work like they state in the user's manual.

[Shannon]

Master set sent to Troemner yearly. All weights used daily are calibrated once a year against master set.

[schorj]

We had a somewhat similiar situation with thermometers. We were cited in a recent AABB inspection because we had not recertified our NIST certified thermometer, that we used to do our yearly checks of all our other thermometers.

The assessors said that these NIST thermometers, just because they were certified in the past, does not guarantee that they are still accurate.

My point was that we checked 30 thermometers against the NIST thermometer and they all read the same as the certified thermometer! Could all the thermometers be wrong??

Needless to say, we were still cited for this. Sometimes we major in the minors.

The assessors did tell us that if we purchased an inexpensive regular certified thermometer yearly, and checked that thermometer against the NIST certified thermometer, we in essence did our own recertification. This sounded fairly reasonable, however in my opinion, unnecessary.

[JohnD]

We provide NIST weight calibrations at our mass lab. Our turnaround time is much quicker than any other calibration labs in the country.

Calibration of weights isn't as simple as placing a weight on a balance and taking a reading. The proper method accepted by NIST is to do a comparison to a known (True Mass which is a calculated value). All the information can be found in the NBS handbook 145. NBS is now known as NIST.

We also provide discounts to blood banks for weight calibrations.

Please visit our website at www.stiservice.com or give us a call.

Always remember the rule of thumb in the metrology industry is that the standard used in a calibration should be when at all possible 4x more accurate then the instrument under test. Even when calibrating thermometers, keep in mind if it is a full immersion type and your unable to immerse completely then a stem temperature correction has to be applied in the calculation.

We also provide Temperature calibrations too. And many other repair/refurbishment services. We also Manufacture the worlds best Tube Sealer and provide the USA in Temp Checks for monitoring temperatures in blood bags.

We work with customers like Ortho Clinical Diagnostic Systems, Chiron, Merck, Astra Zeneca, ARC, New York Blood Center, UBS, the list goes on.

State Technology, Inc.

ISO 9001:2000 registered

510 Heron Drive

Bridgeport, NJ 08014

856-467-8009

fax 856-467-9481

email: emailus@stiservice.com

Regards,

John Dozier