Schaller Messtechnik Humimeter BMA User Manual page 16

Notes for bulk density and bone dry weight (atro) / m³
For determining the bulk density according to the norm EN14961 a
round bucket is used. As the humimeter BMA uses a rectangular
measuring box, we have entered a compensation factor in the
device. This compensation factor has been optimised for wood
chips and therefore can differ when measuring other material
types. The bulk density of biomass material during transport can
change considerably (compacting), when measuring the volume a
material cone has to be considered.
An eventual discrepancy of the bulk density directly influences the
displayed dry weight /m³.
Notes for comparison measurement with drying oven
The humimeter BMA uses a much higher sample quantity than the
drying oven (12-fold to 20-fold quantity of kiln-drying method).
Furthermore, to determine a more accurate average moisture value
in case of inhomogeneous material, the humimeter BMA enables a
large number of measurements within a short time. Considering a
sampling error due to the considerably smaller sample quantity as
well as the content of volatile matters, resin etc. (that are not
water), the kiln-drying method will practically reach an accuracy of
approx. +/- 3%. Therefore, if the measuring values of these two
very different methods of determining the water content are
compared, differences of +/- 3% can be considered to be normal.
In standard EN ISO 18134-2 is declared, that these drying oven
method provides no absolute values. There you receive values
which are comparable only.
Exemption from liability
For miss-readings and wrong measurements and of this resulting
damage we refuse any liability. This is a device for quick
determination of moisture. The moisture depends on multiple
conditions and multiple materials. Therefore we recommend a
plausibility check of the measuring results. Each device includes a
serial number and the guarantee stamp. If those are broken, no
claims for guarantee can be made.
page 16 version 2.2