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High Pressure Densometers are the
accepted standard for measuring the porosity, air-permeability or
air-resistance of materials having low permeability. Typical
materials include coated papers, plastics and membranes. High
Pressure units are recommended whenever a standard unit would
yield excessive measurement times. Manual and automatic units
available. Conform to TAPPI T-536-88 and ASTM D-726-58, Method B.
The densometer test measures the
time required for a specific volume of air (2.5cc to 30cc), at a
constant pressure of 12.33 inches W.C., to flow through a
standard area of the material being tested. The air pressure is
supplied by a weighted inner cylinder floating freely within an
outer cylinder which is partially filled with oil to act as a
seal. The sample material is held between clamping plates having
a circular orifice area of 1.0 square inch (standard).
High pressure units are recommended
whenever a standard unit would yield excessive measurement times.
Porosity readings with the high pressure densometer are much
faster than those taken with a regular densometer. This
difference can be as great as twenty-five times faster since
higher air pressure is used and air volumes are one-tenth those
measured with a standard densometer. Readings also can be
affected by using different adapter plates with smaller orifices
on all models.
The new oil-filled high pressure
densometers replace older mercury-filled models yet feature
identical performance, continued reliability and accuracy. The
only difference is the physical height of the unit (27" with
inner cylinder down).
Obsolete Models 4120 & 4200
contain mercury which may pose personal safety hazards. These
instruments can be converted to oil by replacing the entire upper
cylinder assembly. The conversion must be performed at our Troy,
NY factory and includes packaging for and disposal of the
mercury. Please refer to No. 4050-C Product Bulletin for details.
This model measures porosity and
air-permeability of materials. It includes a 1.0 square inch
clamping plate, adapter and porosity calibration plate. The inner
cylinder is graduated to 2.5cc for the first two spaces and
thereafter each 5cc for a total of 30cc. Clamping pressure is
supplied by turning a knob which raises and locks the lower
clamping plate. Order the automatic digital timing attachment and
instrument leveling base separately.
The No. 4250 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 or porosity. In
dealing with the printability of paper, it has been found that
smoothness is the most important factor in printing quality.
The Gurley No. 4250 H-P-S Tester
measures a given air flow through the sample for porosity tests
and leakage across its surface(s) for smoothness tests. This is
accomplished by changing a variety of adapter and clamping
plates.
This model is identical to the No.
4150 and 4240 for porosity tests and their components.
Additionally, it includes a 0.34 lb. weight, smoothness 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. 4150 and includes the weighted arm assembly found on No.
4250. 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 the smoothness test plate, a
paper punch. 0.34 lb. weight and storage box, the No. 4240
becomes a no. 4250. 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
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