Electronic Densimeter for Plastics
塑料电子密度计
- SKU DET-0001
- Density Testing
- CE (to be confirmed)
- ISO 9001 manufacturing (to be confirmed)
Price on request — FOB / CIF quoted per order
Prices depend on configuration, quantity and destination port.
Key specifications
| Density resolution | 0.001 g/cm³ |
|---|---|
| Density accuracy | ±0.0005 g/cm³ typical |
| Balance capacity | 200–300 g |
| Balance resolution | 0.1 mg |
| Covering liquids | Water, ethanol, surfactant solution |
| Temperature compensation | Automatic or manual entry |
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By Lab Manufacturers China Technical TeamLast reviewed Standards: ISO 1183-1, ISO 1183-2, ISO 1183-3
What is the Electronic Densimeter for Plastics?
An electronic densimeter weighs a plastic specimen in air and in a covering liquid, then calculates density automatically from buoyancy. It is the routine instrument for solid pellets and moulded parts where results to four decimal places are needed quickly.
What is the Electronic Densimeter for Plastics?
An electronic densimeter weighs a plastic specimen in air and in a covering liquid, then calculates density automatically from buoyancy. It is the routine instrument for solid pellets and moulded parts where results to four decimal places are needed quickly.
Overview
The instrument combines a precision balance with an immersion station holding a beaker of covering liquid. The specimen is weighed dry, then weighed again suspended in the liquid, and the software applies the Archimedes relationship using the liquid density at the measured temperature. Typical resolution is 0.001 g/cm³ with accuracy around 0.0005 g/cm³ for well-prepared specimens, and automatic temperature or manual entry of liquid density compensates for ambient variation. Accessories include a floating holder for materials lighter than the liquid, a glass sinker for small specimens, and a basket for multiple pellets. Results can be exported with specimen identity for quality records, and the method is defined in ISO 1183-1 and ASTM D792 for solid plastics.
How does it work?
The classical method applies Archimedes' principle: the sample is weighed in air and again while immersed in a liquid of known density, and the difference gives the sample volume. This suits void-free solid specimens and returns density to three or four decimal places. A density gradient column contains a liquid column whose density varies linearly with height, so a small specimen sinks to the level matching its own density and is read against calibrated glass floats, which is useful for very small or thin samples. Gas pycnometry measures the volume of a sample by helium displacement in a calibrated chamber, so it handles powders and porous or irregular material. Bulk and apparent density methods instead measure the mass that fills a defined volume, which is the relevant quantity for granules, powders and cellular plastics.
What are the key features?
- Automatic buoyancy calculation from two weighings
- Resolution of 0.001 g/cm³ with 0.1 mg balance
- Temperature compensation for covering liquid
- Floating holder for materials lighter than water
- Basket for multiple pellets in one measurement
- Export of results with specimen identity
What are the technical specifications?
A typical electronic densimeter for plastics configuration offers density resolution of 0.001 g/cm³, density accuracy of ±0.0005 g/cm³ typical, balance capacity of 200–300 g, balance resolution of 0.1 mg, covering liquids of Water, ethanol, surfactant solution and temperature compensation of Automatic or manual entry. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.
Which applications is it used for?
The Electronic Densimeter for Plastics is used in polyethylene and polypropylene density verification, incoming pellet identity checks, filler loading estimation in filled compounds and density of small moulded parts. Across the wider Density Testing class, laboratories also deploy it for incoming verification of resin density, filler and mineral content estimation in compounds and crystallinity and formulation consistency checks.
Which standards and certifications apply?
Relevant standards and methods include ISO 1183-1, ISO 1183-2, ISO 1183-3, ASTM D792, ASTM D1895, ASTM D1622, ISO 845 and IEC 61010-1. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.
Temperature control is essential because liquid density and sample volume both change with temperature; record the temperature and apply the liquid's density-temperature table. Remove air bubbles from immersed specimens and from pycnometer chambers, as a single trapped bubble changes the volume materially. Weigh the specimen wet mass promptly to limit evaporation and use a covering liquid that does not swell or dissolve the polymer. Calibrate the balance and verify liquid density with a certified glass float or hydrometer at defined intervals. For bulk density, follow the specified funnel, orifice and cup, since changing any of these changes the result.
How do I select the right Electronic Densimeter for Plastics?
Select an electronic densimeter for routine solid-plastic density measurement where speed and simple operation matter. Confirm the balance resolution and the specimen mass range for your samples, and check whether a floating holder and a glass sinker are included, since these are needed for low-density foams and small fragments. Specify the covering liquid and note whether it must be handled under local solvent rules.
How does it compare with other Density Testing variants?
Match the method to the material form. Solid, void-free mouldings and pellets are measured by immersion balances or by density gradient columns when only a small specimen is available. Powders, porous parts and materials that must not contact a liquid are measured by gas pycnometry. Granules, flakes and powders that are handled in bulk are characterised by bulk or apparent density, and rigid cellular plastics by their own apparent density method with a defined specimen. For specification testing, follow the method named in the material standard: ISO 1183 parts and ASTM D792 give different procedures and tolerances for solid plastics, and results from different methods should not be mixed in one data set.
Full specifications
| Density resolution | 0.001 g/cm³ |
|---|---|
| Density accuracy | ±0.0005 g/cm³ typical |
| Balance capacity | 200–300 g |
| Balance resolution | 0.1 mg |
| Covering liquids | Water, ethanol, surfactant solution |
| Temperature compensation | Automatic or manual entry |
| Typical specimen mass | 1–30 g |
| Data output | USB, RS232, print |
| Power supply | 220 V, 50/60 Hz |
Indicative values for this product class. Final specifications are confirmed on the quotation and in the calibration documents supplied with the instrument.
Applications
- Polyethylene and polypropylene density verification
- Incoming pellet identity checks
- Filler loading estimation in filled compounds
- Density of small moulded parts
Key features
- Automatic buoyancy calculation from two weighings
- Resolution of 0.001 g/cm³ with 0.1 mg balance
- Temperature compensation for covering liquid
- Floating holder for materials lighter than water
- Basket for multiple pellets in one measurement
- Export of results with specimen identity
Frequently asked questions about Electronic Densimeter for Plastics
Distilled water with a wetting agent suits most polyolefins, while ethanol or isopropanol may be needed for materials whose surfaces do not wet readily. The liquid must not swell or dissolve the specimen, and its density at the working temperature must be known. Liquid density is normally entered from a reference table or measured with a hydrometer.
Wet the specimen first and let it stand briefly, then inspect it in the liquid before weighing. A bubble of 1 mm diameter displaces about 0.5 mm³, which is significant for a small pellet. If bubbles persist, a drop of wetting agent or a brief vacuum treatment usually removes them.
Yes. Polyamides absorb water, which increases both mass and volume, and the density change over a normal conditioning cycle can be several thousandths of a g/cm³. Specimens should be conditioned to a defined moisture state or dried and tested promptly, and the conditioning must be stated with the result.
A density gradient column can measure fragments of a few milligrams, because the specimen simply settles at the level matching its density. The immersion method also works if the fragment is large enough to weigh accurately in air and in liquid without significant surface tension error, but very small specimens make both weighings uncertain.
Polymer matrices have densities around 0.90 to 1.20 g/cm³, while mineral fillers are typically 2.6 to 2.8 g/cm³ and glass fibre about 2.5 g/cm³. The measured compound density therefore rises with filler fraction, so a density check detects a loading error quickly, although exact quantification requires ashing or thermogravimetry.
Bulk density is the mass of granules or powder that fills a defined volume, so it includes the voids between particles and depends on particle shape, size distribution and how the container was filled. True density measures only the material itself and is always higher. Both values are reported for powders and granules.
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