Dust monitoring solutions manufacturer Dust Monitoring Services (DMS) has introduced a fully compliant ASTMD1739-98 unit, which includes a bespoke, ultraviolet (UV) stabilised linear low-density polyethylene (LLDPE) bucket and lid.

“After being on the cards for a year, the design of the ASTM-compliant unit was finalised in September after a four-month development period during which our existing stainless steel and fibreglass dust fallout units were redesigned to accommodate our new LLDPE bucket,” says DMS owner Byron Klückow.

The 100% locally manufactured unit was launched at the beginning of October and required the development of a rotomoulded bucket and lid to solve a longstanding compliance issue, as many dust fallout units installed across South Africa, generally, use non-compliant bucket sizes or ineffective solutions to collect dust fallout samples.

The introduction of DMS’s ASTM-compliant unit, specifically the bucket, is going to make a major difference, believes Klückow.

“Up until today, there has been no consistency in terms of bucket size, with 5 ℓ or 6 ℓ plastic buckets or 5 ℓ buckets with extenders used while monitoring dust fallout. Even the diameters of 5 ℓ plastic buckets vary according to the supplier.

“Now we have the correct spec bucket and should be able to have consistency between service providers and the Department of Environmental Affairs (DEA),” he highlights.

ASTMD1739-98, which will soon be the method enforced by the DEA going forward, specifies the use of a bucket with a minimum diameter of 150 mm and a height twice its diameter.

The DMS bucket also includes a screw-on lid with an O-ring to ensure a perfect seal to protect the integrity of samples during transport for analysis at an accredited laboratory. The lid can be reused many times without the risk of damage when opening and closing the bucket, whereas the lids of noncompliant 5 ℓ buckets have a much shorter lifespan. A tight-fitting lid has also been an issue faced by competitors seeking to manufacture an ASTM-compliant bucket.

“The issue with current bucket options is well known to us and we tried to eliminate these in our design, so it was a lot of trial and error with the mould to get the inner diameter and finish correct,” explains Klückow.

The use of rotomoulding to manufacture the ASTM-compliant bucket has addressed the issue of cost associated with other manufacturing solutions.

“The cost of injection moulding has been a limiting factor as the tooling cost didn’t justify the number of buckets required, as the only market that I know of that needs a bucket with such dimensions is the dust monitoring sector,” says Klückow.

As the cost of developing an effective solution has been an issue, many companies have tried to create a cheap solution such as bucket extenders, by blocking off 150 mm polyvinylchloride pipes or employing plastic welding.

“But they all fail in the field owing to prolonged UV exposure during the course of a monitoring programme, or they leak, which affects the creditability of the dust fallout sample. Our unit doesn’t have any of these problems,” claims Klückow.

The DMS LLDPE bucket is moulded as one piece, which eliminates any possibility of leaks or failure, and while costlier than other alternatives, it theoretically has an eight-year design life.

The company has a limited number of buckets in stock but will scale production going into the new year by adding a second mould to increase its stockholding.

“We have had very good interest in the ASTM-compliant bucket and have been approached by a municipality which is interested in purchasing them for enforcement purposes. We have also received interest from operators in West Africa since the bucket is a lot harder wearing than injection moulded 5  buckets, which become brittle and fail after being exposed to harsh conditions for two to three months in the field,” concludes Klückow.