Gas Pycnometer

Gas Pycnometer

The Innova PYC-IA and Innova PYC-IIA Gas Pycnometers are instruments designed to determine the true volume and density of powders and bulk solids through the gas replacement method. These devices use high-precision detectors for volume measurement and density with porosity calculations to provide accurate results. True density refers to the mass per unit volume of a solid in an absolutely dense state after removing the internal pores or inter-particle voids. The Innova PYC-IA and Innova PYC-IIA Gas Pycnometers comply with ASTM B923, C604, D2638, D550, and other relevant standards.


The Gas replacement method is utilized for the determination of true density, based on the Archimedes principle and gas expansion displacement method. In this method, a small inert gas such as helium or nitrogen is used under controlled conditions of the Law of Bohr (PV=nRT). The decrease in gas volume caused by the test sample in the test chamber is measured to calculate the true volume and analyze the true density.

To carry out the test, the displacement gas is pressurized to a target pressure and introduced into a reference volume chamber with a known volume. The pressure is then recorded after stabilization. The valve is opened to allow the gas to expand into the sample chamber, also with a known volume, and the second pressure is recorded after stabilization. The pressure drop ratio is compared to the behavior of the system when a known volume standard undergoes the same process.


ModelInnova PYC-IAInnova PYC IIA
1000 Torr TransducerSingle chamberDual chamber
MethodGas replacement
Sample cell volume10cc up to 300cc (others available)
Sample typeFlat sheet, Hollow fiber, Powders, and bulk solids
Test typeVacuum, High pressure and Ambient
Gas typeHelium and any non-corrosive gas including air can be used
Accuracy± 0.05% of F.S
PrecisionReproducibility is typically to within ± 0.01%
Operating ModelExternal PC or Build in Touch panel PC
Operation typeAutomatic test mode and manual control mode
Temperature controlOption, circulator bath (15℃ to 50℃)
Safety protectsPressure, Temperature (Option)

Gas Pycnometer: Representatives

Seika Machinery Inc Los Angeles Head Office & Demo Center

21241 S. Western Ave.
Suite 140
Torrance, CA 90501 USA
Driving Directions
(310) 540-7310
(310) 540-7930

Seika Machinery Inc Atlanta Branch Office & Demo Center

1580 Boggs Rd.,
Suite 900
Duluth, GA 30096 USA
Driving Directions
(770) 446-3116
(770) 446-3118

Seika Machinery Inc San Francisco Branch Office

23785 Cabot Blvd.
Suite 306
Hayward, CA 94545 USA
Driving Directions
(510) 293-0580
(510) 293-0940
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