IEEE Std 205:2001 pdf free download

IEEE Std 205:2001 pdf free download

IEEE Std 205:2001 pdf free download.IEEE Standard on Television: Measurement of Luminance Signal Levels.
5.2.2 Waveform monitor accuracy
A wavelonn monitor shall be capable of luminance lesel measurements with errors not exceeding 1% of a IV signal displayed with I4OIRE. units on a 170 IRE unit scale. Factors that contribute to instrument measurenlent error include:
a Spot size and Focus
b) Brightness
c) Deflection amplitude
d) Vertical linearity
c) Display rotation
f) Readability of external scaics, including a reasonable allowance for parallax
g) Calibration accuracy. and stability of calibration
5.2.3 Bandwidth
The bandwidth and group-delay characteristics of the waveform monitor shall not significantly alter the characteristics of the luminance filter. A typical waveform monitor will have a frequency response within 2% from 50Hz to 6 MH referenced to 50kHz. and a 2T transient response error of % or less and a 75c input imp-dance with return-loss >36dB to 551 lit,
5.2.4 Scale
An appropnate scale is shown in the left-hand portion of Figure I. together with an illustriftise video signal showing the relation between the scale and the waveform presentation. The zero or reference point of the scale is located at the blanking level, The upper pall of this linear scale is marked from 0 to 120 IRE units. The luminance portion of the video signal is measured on Ibis portion of the scale. The lower part of the scale is marked in linear steps from 0 to —50 units and is where levels of the sync signal can be measured.
5.2.5 TIme-base
The ieform monitor time.buse shall be synchroni.d at both line and field rates and may be switchable to multiples and suhmultipks of those rates to provide a convenient dtspby of portions of lines and fields, or tso lines or two fields,
5,2.6 DC restoration
A sic restoration circuit, preferably referenced to reference blanking or back porch and capable of being disabled, shall be employed 10 prevent vertical shifts of the displayed waveform in the presence of low- frequency disturbances Iavcrage picture level API.). hum. etc.]. The time constants of thcdc restoration circuit shall be short enough so that the above disruptions are prevented or significantly reduced.
5.2.7 Vertical and horizontal centering
A suitable means shall be provided for the alignment of the displayed image with the graticule containing the IRE scale.