AccuPyc II
Gas Displacement Pycnometry System
- Best-in-class density measurements
- High thermal mass design improves measurement stability
- Self-aligning enclosure simplifies operation and guarantees precision
The AccuPyc II Series of Pycnometers (Gas pycnometer) provides high-speed, high-precision measurements for determining the true density of powders, solids, and slurries. The analyst enters the mass of the material and then with a few keystrokes the measurement is initiated, several measurements are performed, and the density of the material is displayed.
Gas pycnometry is recognized as one of the most reliable techniques for obtaining true, absolute, skeletal, and apparent volume and density. This non-destructive technique utilizes the gas displacement method to measure the volume of a material. Inert gases, such as helium or nitrogen, are commonly used as the displacement medium for gas pycnometry. Density determinations from the gas displacement method are more accurate, reproducible, and faster than the traditional Archimedes water displacement method.
Features and Benefits:
Specifications
Operating Environment
Temperature | Stable between 15 to 35 °C (59 to 96 °F) Temperature-controlled AccuPyc: temperature stability is dependent upon specifications of the installed circulator. Recommended range: 15 to 50 °C (59 to 122 °F) |
Humidity | 20 to 80% relative, non-condensing |
Physical
Height | 14.6 cm (5.8 in.) 17.9 cm (7.0 in.), analysis modules for 1-, 10-, and 100-cm³ units |
Width | 27.3 cm (10.7 in.), control module (no chamber) 27.3 cm (10.7 in.), control module (with chamber) |
Depth | 36.2 cm (14.3 in.) |
Weight | 9.3 kg (20.5 lbs), control/analysis unit (1-, 10-, and 100-cm³ units) 7.9 kg (17.4 lbs), analysis module (1-, 10-, and 100 cm³ units) |
Electrical
Voltage | 90 to 264 VAC |
Power | 30 VA |
Frequency | 50 to 60 Hz |
Gases
Research grade helium is recommended. If unavailable, use helium with a dew point of -67 °C (-88 °F) or lower. Carbon dioxide, argon, dry air, or nitrogen can also be used for different applications (a multigas option is available for connection of mulitple gases).
Sample Cups
1 cm³ chamber | 1.14 cm ID x 1.1 cm D (0.45 in. ID x 0.44 in. D) |
10 cm³ chamber | 1.85 cm ID x 3.95 cm D (0.72 in. ID x 1.55 in. D) |
100 cm³ chamber | 4.62 cm ID x 6.18 cm D (1.82 in. ID x 2.43 in. D) |
Analysis
Precision | Reproducibility is typically to within ± 0.01% of the nominal full-scale sample chamber volume. Reproducibility is guaranteed to within ±0.02% of the nominal full-scale volume on clean, dry, thermally equilibrated samples using helium in the 15 to 35 °C range. |
Accuracy | Accurate to within 0.03% of reading, plus 0.03% of sample capacity |
* Should not be installed on a network drive with shared access. Multiple users cannot operate the application at the same time. All users need read/write permission to all directories and subdirectories where the application is installed.
* Due to continuous improvements, specifications are subject to change without notice
Gas Displacement Pycnometry
Principle of Operation
PRINCIPLE OF OPERATION
This technique uses the gas displacement method to measure volume accurately. Inert gases, such as helium or nitrogen, are used as the displacement medium. The sample is sealed in the instrument compartment of known volume, the appropriate inert gas is admitted, and then expanded into another precision internal volume. The pressures observed upon filling the sample chamber and then discharging it into a second empty chamber allow computation of the sample solid phase volume. Helium molecules rapidly fill pores as small as one angstrom
in diameter; only the solid phase of the sample displaces the gas. Dividing this volume into the sample weight gives the gas displacement density.
- Inert gas flows Into sample chamber – valve a opens then closes
- Equilibrium is reached
- Gas flows into second chamber for volume measurement – valve b opens
- Equilibrium is reached yet again
- Volume divided into sample weight determines density
- Pressure vented off to atmosphere – valve c opens
Density Measurement
DENSITY MEASUREMENT
On an elementary level, the volume of a solid material can be calculated by measuring its length, width, and thickness. However, many materials have within their structure surface irregularities, small fractures, fissures, and pores. Some of these voids or pores are open to the surface or closed within the structure of the solid material. Therefore, differences in the material volume depend on the measurement technique, measurement method, and the conditions under which the measurements were performed.
Density Type | Definition | Material Volume | Open-Pore Volume | Closed-Pore Volume | Inter particle Volume | External Void Volume | Addressed by |
True (Absolute | The mass of a substance divided by its volume, excluding open and closed (or blind) pores |
✓ |
AccuPyc II | ||||
Skeletal (Apparent) | The ratio of the mass of the solid material to the sum of the volume including closed (or blind) pores |
✓ |
✓ | AccuPyc II | |||
Envelope | The ratio of the mass of a substance to the envelope volume (imaginary boundary surrounding the particle) |
✓ |
✓ | ✓ | ✓ | GeoPyc | |
Bulk | Mass of the material divided by the volume occupied that includes interstitial space |
✓ |
✓ | ✓ | ✓ | GeoPyc | |
Tap | Apparent powder density obtained under stated conditions of tapping |
✓ |
✓ | ✓ | ✓ | GeoPyc with T.A.P. function |
Highly Adaptive System
HIGHLY ADAPTIVE SYSTEM
The AccuPyc II Pycnometer consists of an integrated control and analysis module. For those who require high throughput, analysis modules are also available in a single configuration, allowing you to attach up to five additional analysis modules to a single controlling unit. Each module has its own gas connection. A variety of sample chamber sizes can be selected to provide the best fit with your samples. The run precision mode allows you to achieve high repeatability. The instrument purges water and volatiles from the sample and then repeats the analysis until successive measurements converge upon a consistent result.
UNIQUE RUN PRECISION
Increases the precision of analysis results by reporting data from five consecutive measurements that are within a user-specified tolerance. This feature allows early termination of analysis, thereby decreasing the number of cycles needed for accurate results.
INTEGRATED CONTROL AND ANALYSIS MODULE
Can control up to five additional external analysis modules
MULTILINGUAL
The AccuPyc may be operated in five languages: English, French, German, Italian, or Spanish
ETHERNET PORT
An Ethernet port on the rear panel of the control module enables you to email reports, send data to a web browser for archiving, or interface with the AccuPyc Windows application
USB PORTS
USB ports on the rear panel of the control module allow for connection to a printer (output of analysis and calibration results in either ASCII or Excel formats) and keyboard (alphanumeric character input). The USB port is also used for installing software upgrades.
SIMPLE CALIBRATION PROCESS
Allows you to easily determine the volume of the instrument sample cell and expansion chambers using a traceable standard volume. After calibration, the cell and expansion chamber volumes are stored automatically
DIRECT SAMPLE MASS INPUT
Sample mass may be directly input from an analytical balance
BAYONET CAP FITTING
Provides superior repeatable seal compared to screw-type fitting
FIVE STANDARD SAMPLE CHAMBER SIZES
1 cm3 , 10 cm3 and 100 cm3
Hardware Versatility
HARDWARE VERSATILITY
MULTIVOLUME KITS
A MultiVolume option allowing you to analyze smaller-sized samples with your current AccuPyc model is available for configurations listed below. Each kit includes appropriate insert(s), reference standard(s), and sample cup(s).
Application
Application | Discussion | Reference |
Powder Metallurgy | Results of many intermediate and final processing steps are controlled by or related to skeletal density of the metal. In addition, the performance of many sintered or cast metal structures may be predicted from the skeletal density of the starting metal powder | ASTM B923 |
Refractory Materials | True density is a useful value for: classification, detecting differences in chemical composition between supposedly similar samples, indicating mineralogical phases or phase changes, calculating total porosity when the bulk density is known, and for any other test method that requires this value for the calculation of results | ASTM C604 |
Calcined Petroleum Coke | The density of calcined petroleum coke directly influences the physical and chemical properties of the manufactured carbon and graphite artifacts for which it is used. Density, therefore, is a major quality specification of calcined petroleum coke and is used as a control in coke calcination | ASTM D2638 |
Soil | The specific gravity of soils that contain extraneous matter (such as cement, lime, etc.) or water-soluble material (such as salt) must be corrected because of the precipitate that forms on the specimen after drying. If the precipitate has a specific gravity less than the parent soil grains, the uncorrected test result will be too low. If the precipitate has a higher specific gravity, then the uncorrected test value will be too high. | ASTM D5550 |
Powder Coatings | Total solids content can be used to determine minimum coverage obtainable with different coating blends. Mixtures of dry pigments can be monitored by comparing measured density with theoretical density based upon composition of the mixture. | ASTM D5965 |
Clear or Pigmented Coatings | Dried film density can be used in the determination of Volatile Organic Compound (VOC) content of clear and pigmented coatings. VOC is required by government regulations. | ASTM D6093 |
Rigid Cellular Plastics | Plastic foams exhibit different properties based upon the ratio of open and closed cells. Insulation foams limit thermal conductivity through pockets of trapped gases contained within closed cells. Flotation devices owe buoyancy to closed air-filled cells that prohibit water entry. | ASTM D6226 |
Pharmaceuticals | Composition of active and excipient ingredients can be monitored and controlled through determination of product density. Polymorphic, hydrated, and amorphous forms of products, as well as purity, can be determined by comparing measured density with theoretical and historical values. | USP 699 |
FERTILIZERS
Knowledge of the bulk density is of interest in package sizing, in calibrating volumetric feeders or applicators, and in determining the storage capacity of bins and transport vehicles. Apparent density information can be used in segregation studies and development of granulation processes. True density measurements are important in
process control and the design of process equipment
MINING CORES
Simple physical measurements of a circular core cylinder’s diameter and length allow the envelope volume to be calculated. A gas displacement pycnometer, with a larger sample chamber designed specifically to accept intact drill cores, provides a low-cost, time-saving, non-destructive technique for measuring the skeletal volume. Knowing the envelope and skeletal volumes allows the total pore volume and percent porosity of the core sample to be determined.
COSMETICS
The presence of air bubbles in cosmetic preparations, such as lipsticks and powder cakes, is undesirable for a
number of reasons. Trapped air can create pinholes and poor appearance in lipsticks and compromise the integrity of cakes. The effectiveness of different methods of air bubble removal can be evaluated by comparing the true density measurements of the material before and after air bubble removal
Configuration/Model Selection
AccuPyc II 1345 Instruments
Sample Cup Capacity | Sample Cup Dimensions | Available MultiVolume Insert Kits | Temp Control Type | Catalog Number |
1 cm³ | 1.14 cm ID x 1.1 cm D | 0.1 cm³ | N/A | 134/50001/00 |
10 cm³ | 1.85 cm ID x 3.95 cm D | 1.0 and 3.5 cm³ | N/A | 134/50000/00 |
100 cm³ | 4.62 cm ID x 6.18 cm D | 10 and 35 cm³ | N/A | 134/50002/00 |
AccuPyc II 1345 Remote Analysis Instruments
Remote analysis modules only. Remote analysis units require connection to a control module or AccuPyc II 1345.
Sample Cup Capacity | Sample Cup Dimensions | Available MultiVolume Insert Kits | Temp Control Type | Catalog Number |
10 cm³ | 1.85 cm ID x 3.95 cm D | 1.0 and 3.5 cm³ | N/A | 134/50040/00 |
AccuPyc II 1345 Temperature-Controlled Instruments
Sample Cup Capacity | Sample Cup Dimensions | Available MultiVolume Insert Kits | Temp Control Type | Catalog Number |
10 cm³ | 1.85 cm ID x 3.95 cm D | 1.0 and 3.5 cm³ | Use with External Recirculating Bath 15-50 °C | 134/50010/00 |
100 cm³ | 4.62 cm ID x 6.18 cm D | 10 and 35 cm³ | 134/50020/00 | |
10 cm³ | 1.85 cm ID x 3.95 cm D | 1.0 and 3.5 cm³ | Integral Thermoelectric Cooling 15-36 °C ±0.1 °C | 134/50050/00 |
100 cm³ | 4.62 cm ID x 6.18 cm D | 10 and 35 cm³ | 134/50051/00 |
Accessories
Quote Accessories
Foam Solution
Foam Solution
FOAMPYC – DENSITY MEASUREMENTS FOR OPEN- AND CLOSED-CELL FOAMS
The AccuPyc II unit can be ordered initially with the FoamPyc application installed. If you have a standard AccuPyc, you can upgrade with a software enhancement. A FoamPyc option for measuring open- and closed-cell foam materials is available in the following configurations for the standard and temperature-controlled pycnometers:
- 10-cm3 nominal cell volume
- 100-cm3 nominal cell volume (for conformance to ASTM and ISO methods
Weighing Solution
Weighing Solution
ANALYTICAL BALANCE
The AccuPyc weighing solution provides one-touch transfer of mass data from the analytical balance directly to the AccuPyc’s Windows software. Direct transfer eliminates user error associated with manual entry of mass data.
- Seamless device compatibility
- One-touch mass data transfer to AccuPyc for automatic calculation of density
- Includes 120 X 0.01 mg electronic analytical balance with calibration weight
Temperature Control Solution
Temperature Control Solution
ACCUPYC II TEC – DENSITY TESTING FOR SEMI-SOLID MATERIALS
This AccuPyc solution can be closely correlated (< 0.15% difference) to results obtained with ASTM Test Method D70-09. The ASTM method is burdensome and time consuming. Our approach offers an expedited, more robust, operator-independent method, with results in minutes.
- Reproducible results in minutes, virtually eliminates operator error
- Integral solution with software for bituminous material testing includes results for specific gravity, volume, and density. As well as reported density corrected to 60 °F.
- Peltier thermoelectric control (15 to 36 °C) provides excellent temperature control/stability and sample handling
- Optional 3.3 cm3 disposable sample cups limit crosscontamination and minimize cleaning of sample chamber between analyses
Consumables & Supplies
Consumables & Supplies
Software Versitility
Downoad Software
Data Representation
The AccuPyc II can be operated with a full keyboard or an optional Windows® interface that provides exceptional reporting and archiving capability. Both versions include direct sample mass input from a balance and cycle-based displacement volume reporting. With the Windows interface, features such as time-based pressure equilibration reporting and additional calculations such as percent solids content and total pore volume are included. Operational status can also be continually monitored in a status window on the monitor screen.
Combined Report
- Summary Report
- User-Defined Tabular Reports
- Volume vs. Cycle #
- Density vs. Time
- Total Pore Volume vs. Temperature
- Density vs. Cycle #
- Density at 60 °F
- Volume at 60 °F
- Options Report
- Equilibration Report
- Sample Log
- Specific Gravity
AccuPyc II 1345 Resources
Application Notes
- Density Determination of Plastic Film Using the AccuPyc
- Measuring the Percent Solids of a Slurry with the AccuPyc 1330 Pycnometer
- Ultraprecise Calibration for the AccuPyc
- Determining the Open Cell Content of Rigid Cellular Plastics with the AccuPyc Pycnometer
- Sample-Weighing Precision with the AccuPyc, 1-cm3 Capacity
- Asphalt Density Using AccuPyc II TEC
- Understanding the Uncertainty and Precision Specifications for the AccuPyc
- Analyzing Liquids with the AccuPyc