OIML R-50 Belt Scale Testing Requirements

Posted in: , on 7. Jul. 2004 - 04:20

Learned Readers,

I am writing operating software for Rice Lake Weighing's 920i indicator/controller as a conveyor belt scale. I have written the span calibration procedures for static weights, but I would also like to include a material testing routine. Currently the dynamic span can be manipulated manually, so a material test can be performed by typing in a correction. I have not included curve fitting for various feed rates, as We have always been under the opinion, that if a system must have multiple span corrections, the scale installation or application is probably unstable as a certified scale.

I have attended a presentation by Mr. Paul Chase on the differences between the OIML R-50 testing procedures and the NIST HB 44 procedures. I have performed and assisted with certifications on a number of conveyor belt scales in the US, but I have never wittnessed a OIML R-50 test.

I would like an opinion on the R-50 tests. From what I remember from Mr. Chase's presentation, the R-50 tests were dependant on material feed rates over short durations. The NIST tests were written around a "tested as used" philosophy. Is there an online reference for the OIML R-50 material test? Are most belt scales installed internationally tested using

OIML R-50 or NIST HB44? Or is OIML R-50 only used in EU block countries?

Thank you for your time and consideration,

regards, Todd Dietrich todd@kvsco.com Kaskaskia Valley Scale Co. http://www.kvsco.com
steve.davis
(not verified)

Re: Oiml R-50 Belt Scale Testing Requirements

Posted on 12. Aug. 2004 - 04:32

Good Day Todd,

OIML R 50 is applicable here in Australia, although it has been rebadged as NSC R 50. We would use this system of calibration on weighers used for trade purposes, as it is legally required by the various Acts in place here.

I can't really comment on the differences between this and NIST 44, as we would not use this guideline.

OIML has a website that may answer your questions.

http://www.oiml.org/

Regards

Oiml R50

Posted on 11. Sep. 2007 - 11:12

Hello Todd and Steve,

I correspond with Paul Chase a bit and yes, as Steve says we use OIMLR50 here, or at least a close derivitive.

Todd, you will need curve fitting. Thats as much as I think it fair to tell a competitor.

I agree with your comments in general about weigh frame stability. But does Rice Lake build serious weigh frames? Where can I see one on the net?

Regards L. Ian Burrell Managing Director CONTROL SYSTEMS TECHNOLOGY http://www.controlsystems.com.au ___________________________________________________ ( +(61) 2 9584 2566 Mobile +(61) 419 292 604 Ê +(61) 2 9584 8080 + PO Box 249 Mortdale NSW, Mortdale NSW 2223, Australia Unit 9, 41-45 Lorraine St, Peakhurst NSW 2210, Australia : iburrell@controlsystems.com.au