Overview
EN ISO 1923:1995 - Cellular plastics and rubbers - Determination of linear dimensions (ISO 1923:1981) specifies the measuring equipment and procedures for determining linear dimensions of sheets, blocks or test specimens of cellular materials (flexible and rigid). Adopted by CEN from ISO 1923:1981, this standard defines instrument selection, measurement technique, gauging pressure and result reporting to ensure consistent, repeatable dimension data for foam products.
Keywords: EN ISO 1923, cellular plastics, cellular rubbers, linear dimensions, foam measurement, dimensional testing
Key topics and technical requirements
- Scope: Measurement of the shortest distance between two defined points, lines or parallel planes on cellular materials (sheets, blocks, specimens).
- Measuring equipment and recommended accuracies:
- Dial gauge (reading accuracy 0.05 mm): used when 0.05 mm accuracy required; gauging pressure specified as 100 ± 10 Pa; suitable for many specimens (may require specific measuring surface).
- Micrometer (reading 0.05 mm or better): restricted to rigid cellular materials; measuring surface minimum diameter 5 mm and at least five times the average cell diameter.
- Sliding caliper (vernier, reading 0.1 mm): used where 0.1 mm accuracy is appropriate.
- Metal rule or tape (graduated mm, reading 0.5 mm): for dimensions where coarse accuracy (0.5–1 mm) suffices.
- Measurement procedure:
- At least five measurement locations, widely separated to capture variability.
- At each location take three readings, use the median of the three; then compute the average of the five medians.
- Avoid distortion or damage to specimens during gauging.
- Rounding/reporting rules:
- Dial gauge / micrometer results rounded to 0.1 mm.
- Sliding caliper results rounded to 0.2 mm.
- Metal rule/tape results rounded to 1 mm.
- Annex example: test apparatus with base plate, screw micrometer, 10 cm² aluminium plate to impose 100 ±10 Pa (lamp-circuit indicator) and calibrated spacer blocks (tolerance 0.01 mm).
Applications and users
- Quality control and incoming inspection of foam sheets, blocks and molded parts
- R&D and product development for polyurethane, polyethylene, PVC and rubber foams
- Accredited test laboratories performing dimensional conformity tests
- Procurement and specification writers who need reproducible dimensional data for foam components
- Regulatory or certification bodies requiring standardized measurement procedures
Related standards
- ISO 1923:1981 (original international text) - adopted by CEN as EN ISO 1923:1995
- Developed jointly by ISO/TC 45 (Rubber) and ISO/TC 61 (Plastics)
Use EN ISO 1923 when consistent, comparable linear-dimension measurement of cellular plastics and rubbers is required across manufacturing, testing and compliance workflows.
