Standards & Testing

Standards Numerous standards have been developed in various countries for cassettes and screens These include DIN (Germany), ANSI, IEC, JS (Japan), MIL (U.S. Military), ISI (India) and others. With emergence of ISO standards in Europe, various global standards are veering towards ISO standard 4090. The ISO 4090 and ISO 4090-1 standards for cassette and screen define dimension, dimensional tolerances, geometrical accuracy, absorption standards, design parameters as well as stipulate testing methods. Testing Key areas for performance measurement of cassettes and screen, on the basis of ISO 4090 are: > Film-Screen Contact Test Contact is the key measurement of radiological image quality of the cassette. Good contact leads to accurate diagnosis. Contact test should be ideally done once a year. > Speed & Resolution Test Quantum of X-Ray dosage required to raise the density of the X-Ray film to the desired level depends on the Screen speed. A screen speed of 400 together with the use of a regular speed film addresses the requirements of most of the general radiological examinations. Resolution of screen is the key to clear film reading. > Cassette Light-proofness Test Light leakage in diagnostically important areas, on the edges of a film leads to loss in portions of an X-Ray image. The cassette has to be appropriately designed, engineered and must use optimum construction elements to result in light-proofness. > Cassette Durability Test Durability in cassette is essential for maximizing the return on investment in cassettes. A durable cassette should be able to withstand periodical accidental drops during usage.