Wensar HPB201 - Underfloor Weighing; Density Determination (Hydrostatic Weighing)

9
Follow these steps:
a) Place as many pieces to add-up as required by the reference quantity. Press the “COUNT” key, display
“1” that means into the counting mode, Press the [UNIT] button to enter the setting menu. The display
now shows the number "1" and the unit "Pcs". Using the [UNIT] button select the reference quantity (1,
10, 20, 50, or 100).
b) After successful reference determination the current quantity is displayed and the unit “Pcs”.
c) Remove reference weight. The balance is now in piece counting mode counting all units on the weighing
plate.
6.7 Underfloor weighing
Objects unsuitable for placing on the weighing scale due to size or shape may be weighed with the help of
the underfloor weighing device.
Proceed as follows:
 Switch off the balance
 Open the Sealing cap at the balance bottom.
 Suspend hook for underfloor weighing carefully and completely.
 Place weighing balance over an opening.
 Attach load to hook and carry out weighing procedure.
 Always ensure that all suspended objects are stable enough to hold the desired
goods to be weighed safely (danger of breaking).
 Never suspend loads that exceed the stated maximum load (max) (danger of
breaking).
 Always ensure that there are no persons, animals or objects that might be damaged
underneath the load.
 After completing the underfloor weighing the opening on the bottom of the
balance must always be closed (dust protection).
7 Density determination (Hydrostatic weighing)
According to the Archimedes’ principle, any object, wholly or partially immersed in a fluid, is buoyed up by
a force equal to the weight of the fluid displaced by the object.In other words, an immersed object is buoyed
up by a force equal to the weight of the fluid it actually displaces.
For the density determination of solid material, the solid is weighed first in air and then in the measuring
liquid. Because of the density of the water is 1.0 g/cm ³, can determine the volume of the displaced water
and also the volume of object. From the weight difference results the buoyancy calculates the density.
 The density is determined with help of the underfloor weighing device.
 Hydrostatic density determinations succeed only with the objects, which have a
higher density than water (1 g/cm
3
).
Example:
A piece of metal in the air weight 100 g and weighs 80 g in water. Therefore, the object has 20 g (= 20 cm³)
water displaced. Its volume is therefore 20 cm³. Now it is easy to determine the density of the metal piece.
Density determination of solids