Precision Samplers (PSI) is very proud to announce that it has, in partnership with Sampling Associates International (SAI), developed a new device to sample bulk materials from moving conveyors. This device is called a Mechanical Part-stream Sampler (MPS) and has already been installed at multiple coal export terminals in the United States. While the initial installations have been to sample coal and petroleum coke, the MPS can be customized to sample any bulk material.

The MPS is designed for “Condition C – Part-stream Cut” sampling according to ASTM and is governed by ASTM Standard D6609 for coal. Part-stream sampling produces a Judgment sample not a Probability sample so it does not replace full stream mechanical sampling. But the MPS is an important and effective sampling option when mechanical sampling systems are inoperative- or at locations where a mechanical sampling system is not economically justifiable. For more detailed information, please click here to access the technical article on the MPS.



The main features of the patented MPS are:

  • It has all stainless steel construction for long term corrosion prevention
  • There are two alternating sample scoops to reach both sides of the conveyor
  • The scoops are capable of reaching deeper than a human can with a shovel
  • The scoops operate in the same direction of the material flow
  • The frequency of sampling is programmable and is typically based on the lot size and conveyor flow rate
  • It has a very small footprint on a conveyor belt and can easily be retrofitted



The main benefits are as follows:

  • First, Mechanical Part-stream sampling is much safer than manual belt sampling. No human is exposed to the moving conveyor belt, rolling idlers, or extreme weather.
  • Secondly, it removes the human element in the timing of the sample increments, or human judgment in the selection of material into the sample. By customizing the scoops to reach deep into the material, the particles with a non-zero chance of being selected for the sample are minimized.

When an MPS is paired with a full mechanical sampling system, the terminal can continue loading when the sampling system is offline for any reason - without waiting for the sampling system to be repaired. This is extremely important at terminals that do not allow manual belt sampling due to the high speed of their conveyors. In addition, the MPS reduces down time by freeing the sampling technicians from manually collecting the samples so that they can concentrate on repairing the sampling system.

Essentially, the MPS provides the best possible Judgment sample when mechanical sampling is not available.

Bulk materials with wide quality variations in the particles of different sizes may not be suited for sampling with an MPS. However, the initial installations in the USA show excellent comparative results.

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