Overview
ISO 14648-2:2001 - Micrographics - Quality control of COM recorders that generate images using a single internal display system - Part 2: Method of use - specifies practical methods for using the software test targets defined in ISO 14648-1. The standard guides initial acceptance, optimization and periodic quality control of Computer Output Microfilm (COM) recorders and microform production (microfiche/microfilm) by detailing test procedures, measurement points and pass/fail checks.
Key topics and requirements
- Test target usage: Use the software test targets from ISO 14648-1 to generate full microfiche or an equivalent length of microfilm for testing and record-keeping.
- System setup and warm-up: Verify COM recorder and processor conditions, appropriate film type and processing (fresh chemicals, correct temperatures) before testing.
- Exposure optimization: Produce target images across a range of intensities to select the optimum exposure - where the narrowest font widths appear slightly underexposed and the thickest slightly overexposed.
- Density measurement: Measure visual diffuse transmission density with a densitometer conforming to ISO 5-3 and ISO 5-2. Record maximum and minimum density areas and monitor halftone consistency. Recommended density ranges for several film/process types are provided (e.g., silver gelatin conventional printing: density min 0.75, background 0.15 or 0.10).
- Reduction ratio: Determine horizontal and vertical reduction ratio using borders or measuring scales on the test targets; typical tolerances are around 1% of the stated value (consult manufacturer specs).
- Resolving power and focus: Use resolution charts at target positions (corners, centre) and a microscope or calibrated reader to determine limiting resolution and check focus.
- Character legibility and diagonal-line checks: Inspect designated character areas (EHN, OCR-B, alternate fonts) and diagonal lines for straightness and stepping.
- Record keeping and routine checks: Establish an initial quality reference microform and perform periodic checks to compare against reference results; record exposure settings, densities, resolved pattern and reduction ratio.
Applications and users
ISO 14648-2 is intended for:
- Micrographics technicians and service bureaus
- COM recorder manufacturers and equipment calibration labs
- Records managers, archivists and government agencies producing microforms
- Quality managers implementing microfilm/microfiche quality control programs
Practical benefits include consistent image quality, repeatable exposure/process settings, objective density and resolution metrics, and traceable acceptance records for archival and legal compliance.
Related standards
- ISO 14648-1: Characteristics of the software test target
- ISO 8514-1 / ISO 8514-2: Alphanumeric COM test slide characteristics and methods
- ISO 5-2, ISO 5-3: Density measurement geometry and spectral conditions
- ISO 6196 series: Micrographics vocabulary and definitions
Keywords: ISO 14648-2:2001, COM recorder quality control, micrographics, microfiche, microfilm, exposure optimization, densitometer, reduction ratio, resolving power, test targets.