Acer AL2002 AL2002 Service Guide - Page 16

15 Go to cover page 5.2. Contrast ratio (CR) The contrast ratio is determined by using a photometer (CA-210) to measure the maximum and minimum luminance in front of monitor after at least 30 minutes warm up. It shall be test at 1680x1050/60Hz mode and full white/full black square pattern with contrast/brightness in default value. The values specified are at an approximate distance 20 cm from the LCD surface and at 0 viewing angle. The contrast ratio is calculated as below: CR = (Max. full white luminance) / (Max. full black luminance) CR = 800: 1(typ) 5.3. Response time The response time is defined as below: Tr + Tf: 5 msec typ. 5.4. Viewing angles The viewing angles are measured at CR=10 as below: Horizontal Left: 80 degrees typ. (M201EW02 V1); Right: 80 degrees typ. (M201EW02 V1); VerticalUp: 80 degrees typ. (M201EW02 V1); Down: 80 degrees typ. (M201EW02 V1);