Introduction
Densometers are the accepted
standard for measuring the porosity, air-permeability or
air-resistance of sheet-like materials such as papers, wovens,
plastics and membranes. All Densometers measure the time required
for a given volume of air (25cc to 400cc) to flow through a
standard area of material being tested under light uniform
pressure. Certain models such as the S-P-S Tester are also used
to measure surface smoothness and material softness. Manual and
automatic units available. Conform to TAPPI T-460, ASTM D-726-58
& D-202-77, APPITA/AS 1301-420, BS 5926, CPPA D-14, ISO
5636/5, SCAN P-19 & P-53.
The Densometer test measures the
time required for a given volume of air (25cc to 300cc) to flow
through a standard area of material tested, under light uniform
pressure. The air pressure is supplied by an inner cylinder of
specific diameter and standardized weight, floating freely within
an outer cylinder partly filled with oil to act as an air-seal.
The sample material is held between clamping plates having a
circular orifice area of 1.0 (standard), 0.25 or 0.1 square inch
(optional).
Densometer readings may be evaluated
on both a direct or indirect basis dependent upon the material
and test purpose. They are a direct test of materials which are
intended to either resist or permit the passage of air.
Indirectly, they are used to measure other physical properties
which affect the flow of air through a porous sheet.
- In manufacturing and printing,
to control the selection of materials affording the
appropriate degree of liquid (ink, varnish, sizing)
absorption.
- To test filters, porous bags
& materials where controlled porosity is essential.
- To test insulating materials
for air resistance.
- To supplement other physical
tests enabling regulation or strength of manufacturing
process to give the desired formation, appearance or
strength since there is a close correlation in a given
material between air permeability and these other
properties.
The most popular Densometer sold for
measuring porosity and air permeability in materials of average
values. With options such as smaller orifice plates, materials of
lower permeability may be effectively tested. By using a 5 oz.
cylinder, materials of a higher permeability can be tested (Model
4118).
The Model 4110 includes a 20 oz.
cylinder and 1.0 square inch orifice lower clamp plate and upper
adapter. The 20 oz. cylinder is graduated to 25cc for the first
two spaces and 50cc for each space thereafter, for a total of
300cc. Typical of all new-style densometers, clamping pressure is
supplied by turning a knob which raises and locks the lower
lifting assembly and clamp plate. Both the automatic timer and
instrument base are recommended with these densometers and are
ordered separately.
Model 4118N GENUINE
GURLEYTM Densometer
The Model 4118 is a Model 4110 with
a 5 oz. cylinder in place of the 20 oz. inner cylinder and 0.1
sq. in. clamp and adapter plates instead of the 1.0. It is used
to test fabrics and other more permeable materials for porosity,
permeability and air-resistance.
In cases where the sample being
tested is still too porous for an accurate reading, the Model
4301 Permeometer would be recommended.
The No. 4190 was originally
developed to test the printing quality of paper. In more recent
years, its use has spread to other industries in testing or
checking other material surfaces for smoothness, softness or
porosity. In dealing with the printability of paper, it has been
found that smoothness is the most important factor in printing
quality and softness is usually secondary.
The Gurley No. 4190 S-P-S Tester
measures a given air flow through the sample for porosity tests
and leakage across its surface(s) for softness or smoothness
tests. This is accomplished by changing a variety of adapter and
clamping plates.
This model is identical to the No.
4110 and 4140 for porosity tests and their components.
Additionally, it includes a 0.34 lb. weight, smoothness test
clamping plate, softness test clamping plate, punch and accessory
storage box. Both the automatic digital timer and instrument base
are recommended and should be ordered separately.
This model is identical in function
to No. 4110 and includes the weighted arm assembly found on No.
4190. Uniform dead-weight clamping pressure for tests is supplied
by the unweighted lever arm or by the addition of either 0.34 lb.
(optional) or 2.0 lb. (standard) weights. These combinations
produce clamping pressures of 3.2 psi, 9.6 psi and 40.5 psi
respectively.
With the addition of several test
plates, a paper punch. 0.34 lb. weight and storage box, the No.
4140 becomes a no. 4190. Order the digital timer and base
separately.
The Model 4320 Programmable Digital
Timer is designed specifically for all Gurley Densometers and
High Pressure models. The Model 4320 not only increases the
accuracy and productivity of these instruments, but provides
recording and computing capabilities that will absolutely
minimize the possibility of operator error. Both RS-232 and
Centronics output to a variety of devices, including most
printers and PC's.
Other Model 4320DN features include:
- Automatic & manual program
options
- Calculates mean & standard
deviation
- Built-in calibration program
- Easy to read graphic display
- Fits all GENUINE GURLEYTM
Densometers
- User Programmable
- Date/time stamp
- Automatic sensitivity
calibration
|
