Compulsory Proactive Monitoring of refiners' technical competence in refining and assaying ensures that the high standards required for LBMA Good Delivery List accreditation are maintained.
All Good Delivery refiners have been required to undergo Proactive Monitoring (PAM) since the scheme was introduced in January 2004.
Overview of the Proactive Monitoring (PAM) Programme
The PAM programme reviews the assaying competence of refiners on a three-yearly basis. In addition, it checks that they continue to meet the minimum requirements for refined production and tangible net worth on an annual basis. Three years after the date of original listing, refiners receive a letter from the LBMA instructing them to participate in the programme.
To assist the LBMA with the programme, a number of supervisors are appointed to witness the dip-sampling operation that provides samples for testing by the LBMA’s Referees. Generally a Good Delivery refiner that's listed on both the gold and silver lists will undertake gold and silver PAM at the same time. An exception to this might be where the first listing dates don't coincide.
PAM Assay Testing
Gold and silver refiners are required to undergo a supervised dip sampling process taken from a normal melt. Two of the samples are shipped to the LBMA to be check assayed by the LBMA’s Referees whilst the remainder stay on site. The refiner submits its own analysis of one sample, which is then compared with the referee’s results to determine a pass or a fail.
All gold refiners must be capable of assaying within the range of 995-999.9. Those which normally only produce four-nines gold are therefore required to purchase a set of six gold reference samples from the LBMA. These samples cover the full range from 995 and above. The refiner submits its assay results to the LBMA for comparison with the mean assay values previously provided by the referee. Full details of this process are explained in Annex I of the Good Delivery Rules.
Details of when a refiner last completed PAM are shown on the Good Delivery Lists, which can be accessed using the Search facility on the right hand side of the page.