Sample Handling

Sampling and uniform sample preparation and sample application before a drying is important to obtain repeatable moisture results.

Safety information

  • Achtung.jpgSome samples require particular care as they can harm people or damage objects. These include combustible, explosive, toxic or corrosive substances and/or samples which release these substances when dried/heated.
  • Never dry combustible or explosive substances. If in any doubt, use small sample volumes (max. 1 gram) and low temperatures.
  • Carry out a risk analysis (e.g. with regard to risk of explosion, combustibility, toxicity and corrosiveness of sample and the vapors released when heated).
  • If necessary, work in a fume cupboard (adjustment should then be undertaken there).

Warning: The surface temperature of the radiator is higher than the measurement temperature and hence may ignite combustible vapours as they pass by.

Note: Please note that the user bears all responsibility and liability for damage resulting from the use of the aforementioned types of samples.
Precision with Highspeed

Präzision mit HighspeedThe Halogen Moisture Analyzers offer both precision and speed. You save time and costs and increase efficiency.

Industry Solutions
Method Database

Guide to Moisture Analysis

Sample pans

  • Schalen.jpgOnly use clean sample pans for moisture determination.
  • Do not use deformed sample pans.

Tip: Using single-use aluminum sample pans guarantees reliable measurements free from the influence of residue remaining from previous samples or cleaning agents. These aluminum sample pans are also available in a reinforced version. These are suitable for samples which contract when drying and may deform the pan.
Please dispose of the used pans properly.

Sampling

Probennahmea.jpgThe way in which samples are taken has a major impact on the reproducibility of the measurement results:

  • Representative of total volumeContainer voll-neu.jpg
  • Ensure homogeneity (mixed well), e.g. mix and stir the total volume first etc.
  • Sufficient sampling
  • No addition or removal of moisture when taking samples (work as quickly as possible)
  • If measurements are not being taken straight away: Store in airtight container without an air cushion (fully filled).

Sample preparation

Probe schneiden.jpgThe correct preparation of samples once they have been taken is also key to repeatable and reliable results.
  • Ensure even granulation (particle size).
  • If necessary increase the sample surface area by breaking up the sample. This will ensure a better and faster release of moisture during drying (faster diffusion of moisture to the surface).
  • Moerser.jpgThe sample should not be heated at this stage as this would cause moisture to be lost during preparations.
Mechanical crushing can be carried out e.g. using a mortar, grinder (watercooled) or simply by cutting.

Tip: You can increase the surface area and therefore speed up the drying of liquids by using a glass-fiber filter.

Sample application

Container-neu.jpgAn evenly spread sample results in a homogeneous distribution of heat throughout the product being measured and the moisture can diffuse evenly out of the sample. This generates results which are easier to reproduce.
  • Carefully mix your sample before adding to the sample pan.
  • Always use the same volume of sample to achieve good repeatability.


  • Probenaufgabe1.jpgUse the right sample volume. The pan should be thinly and evenly covered with the sample over the total surface area.









  • Probenaufgabe2.jpgSpread the sample evenly over the pan (do not build up piles).








Influence of sample weight on repeatability and length of measurement:
Messdauera.jpg
A higher sample weight will mean that more water is evaporated and moisture determination will take longer. In addition, too large a sample volume can result in an uneven distribution of heat and thus to less precise results. On the other hand, repeatability decreases (higher standard deviation) as the sample weight decreases:

  • Standard deviation for 2 g sample1: 0.05%
  • Standard deviation for 10 g sample1: 0.01%
wiederholbarkeita.jpg
1Assuming an ideal sample where all of the moisture can always be removed without causing decomposition (e.g. moist sand). Deviations result from the substance-dependent uncertainty and the repeatability guaranteed by the instrument (in this case: HR83). In reality, differences in measurements occurring in one series of measurements (not ideal samples) may be greater than the values shown in the table.