Arizona MAX-5000XL - Manual (Page 65)

AZI Customer Service 800-528-7411 or 602-470-1414 Page 65 of 92
6.2. Preparing Granular and Powdery Samples
The MAX 5000XL can be used to test a wide range of products from finely ground,
low-moisture powders to high-moisture slurries. For best results, the sample should
be of a uniform particle size distributed evenly over the sample pan. If sample
material is collected into a jar or sampling bag, shake the jar or bag to produce a uniform
mixture. Liquid samples should also be mixed or shaken to ensure a more homogeneous
mixture. Large chunk samples, such as charcoal or cookies, should be crushed or ground
to smaller pieces approximately 1/4" or less in diameter. For best results, take care not
to over-grind the sample, causing it to heat up and causing moisture loss.
Some samples, such as dried vegetables, may also need to be ground. The smaller
pieces will easily release moisture during testing, leading to shorter test times and more
repeatable results. Solid, granular sample material should be shaken onto the pan from
a spoon; shaking sample directly from the collection jar will usually deposit only the larger
granules, not a representative mixture. Liquid samples or slurries can be spooned or
poured onto the sample pan; however, a pipette or sampling straw will collect a uniform
mixture of the sample. All samples should be evenly distributed over the sample pan.
6.3. Preparing and Testing Liquid Samples
Some liquid samples will dry slowly, even at high temperatures. Drops or puddles may
form on the pan and dry slowly as the sample concentrates. A skin may form which limits
evaporation from the interior. Long test times (greater than 25 minutes) and low percent
moisture (or high percent solids values) suggest incomplete drying. Pre-dried glass-fiber
filter paper and flat-bottomed pans are recommended to successfully test samples such
as these.
The glass-fiber filter paper, AZI P/N 990-0003, serves as a support for the liquid sample.
The sample is absorbed through the paper for more even and rapid evaporation to
reduce test times. Waffle-bottomed sample pans are not recommended for use with filter
paper. The liquid sample may soak through the filter paper and collect in puddles in the
pan's depressions. Flat-bottom pans are available from AZI as P/N 990-0010. Call AZI
parts sales at 800-528-7411 or 602-470-1414 to order.
Occasionally, some samples cannot be absorbed into the filter paper. At the end of the
test, examination of the sample pan shows the sample sitting high above the filter paper
with a thick crust. The crust may be singed from the heat or even show bubbling where
vapor has been trapped beneath the surface. %SOLIDS results will be high or
%MOISTURE results will be low. Samples such as these are treated differently: After the
sample has been added to the sample pan, remove the pan from the test chamber and
place it onto a flat surface. Grasp part of the filter paper (tweezers are suggested) and flip
it over so that the sample lies between the pan and the paper. Squash the sample with
a flat-bottom glass or jar to a uniform layer. Return the sample pan to the test chamber
and close the lid. The upper filter paper surface absorbs moisture from the sample and
minimizes bubbling and spattering to produce more accurate, reproducible results.