ML20198B073

Issue a to DD-CRL-1, Design Directive for CRT Location

ML20198B073
Person / Time
Site:	Fort Saint Vrain
Issue date:	03/08/1984
From:	PUBLIC SERVICE CO. OF COLORADO
To:
Shared Package
ML20198B035	List: ML20198B030 ML20198B069 ML20198B073 ML20198B090 ML20198B123 ML20198B132 ML20198B141 ML20198B146 ML20198B152
References
DD-CRL-1, NUDOCS 8511060288
Download: ML20198B073 (6)

Text

PUBLIC SERVICE COMPA N Y U t- COLUHADO FORI ST VR AIN NUCLE AR GENE R AT!NG ST ATION DD-CRL-1 1ssue A 6

Page 1 of 6 DESIGN 0:RECTIVE for CATHODE RAY TUBE

- LOCATION PREPARED BY: REVIEWED BY: APPROVED BY:

lht) ~ Is & '[bg hy h

/ 4 FOREWORD: Cathode Ray Tubes (CRTs) providing interface between the computer output and operating personnel shall be located for maximum readability with respect to the operators position and activity with the operating environme,t. The location of CRT displays falls in three categories: t,a) the CRT is mounted in a desk-type console at whicn the operat)r is seated; (b) the CRT is mounted above a benchboard or canel with tne operator having some lateral freecem of movement at tN work station; (c) the CRT is mou,ted on a stand, or pe'-haps on a desktop, with some capability for rotating or moving it to suit the needs of a variety of users. The guidance in this directive deals with those factors which should be considered regardless of type of installation, as well as the parameters which are dependent on the type of installation and the rature of the physical relationship between CRT and operator.

SELECTION CONSIDERATICNS I. VIEWING OISTANCE - Viewing distance should be greater than 18 inches.

II. VIEWING ANGLE - The minimum angle between the operator's actual line-of-sight (LOS) as measurec from the acerator's normal wark station, and tne plane of the display screen shall be 45 or greater in either the horizontal or vertical direction. See Figure 1)

III. MOUNTING IN CONSOLES - When CRTs are permanently mounted in consoles, the console configuration, dimensions, and type of use (such as seated, sit-stand, or standing) affects the CRT/ operator interface. Consoles in which CRTs are installed shall conform to the guidelines of directive CON-1.

IV. VISIBILITY OF DATA -

All data and messages on the CRT screen shall be within the unoDstructed view of an I operator at the normal work station.

l 8511060280 851029 l hDR ADOCK 05000267 n PDR FORM 372 22 3643

PUBLIC SERVICE COMPANY OF COLORADO FORT ST VRAIN NUCLE AA GENERATING STATION CD{RM Issue A Page 2 of 6 V. REFLFCTED GLARE CRT screens shall be installed to

_ minim ze or eliminate reflected light (or glare) at normal i

operatar viewing angles.

VI. SREEEN .UMINANCE - Ambient illumination should contribute no more t>an 25% to screen luminance through diffuse reflection and phosphor excitation.

VII. SCREEN LOCAT.'ON, SEATED OPERATORS A. CRT di s,,l ay s which require frequent or continuous monitorin,1, or which may display important (e.g.,

alarm) in'ormation, shall be located within the following limits as measured from the normal operator work station (see figure 2).

1. Horizontal limits-Not more than 35 to the left or tight of the operator's straight-ahead LOS.

2. Vertical lirits-Not more than 20 above and 40*

below the operator's horizontal LOS.

B. CRT displays which do not require frequent or continuous monitoring and which will not display important (e.g., alarm) i n .'o rma ti o n , shall be located whithin the foilowing limits (as measured from normal operator work stations which permit full operator head and eye rotation (see figure 3).

1. Horizontal limits-Net more than 95* to the lef t or right of the operator's straight-ahead LOS.

2. Vertical limits-Not more than 70 above and 90 below the operator's horitontal LOS.

VIII. SCREEN LOCATION, STANDING GPERATORS A. CRT displays which require freq.ent or continuous monitoring, or which may display 'mportant (e.g.,

alarm) information, shall be located within the following limits as measured from the normal operator work station:

1. Horizontal limits-Not more tha.1 35* to the lef t or right of the operator's st aight-ahead LOS.

2. Vertical limits-Not more than 35 above and 25 below the operator's horizontal LOS.

FORM 372 22 36 4 J

PUBLIC SERVICE COMPANY OF COLORADO 50RT ST. vR AIN NUCLEAR GENE R ATING ST ATION , , , , , ,

us unL-1 Issue A Page 3 of 6

8. CRT displays which do not require frequent or continuous monitoring, and which will not display important (e.g., alarm) information, shall be located within the following limits (as measured f rom normal operator work stations which permit full cperator head and eye rotation):

1. Horizontal limits-Not more inan 95 to the lef t or right of the operator's straight-aheac LOS.

2. Vertical limits-Not more than 80 above and 90 below the operator's horizontal LOS.

ASSOCIATED DIRECTIVES 00-00 Requirement and Guidance for Preparing Design Directives DD-CRT Cathode Ray Tube Selection DD-CON Consoles DD-SLS Screen Layout and Structuring SOURCE MATERIALS AND REFERENCES

- NUREG-0700

- Human Factors in Engineering McCormick, 1976

- Human Factors in Design ERDA 76-45-2 FORM 372 22 36 0

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PUBLIC SERVICE COMPANY OF COLORADO FORT ST. VR AIN NUCLEA A GENEG A *i'.O STATION DD-CRL-1 ISSUE A Page 5 of 6 VERTICAL LIMITS D g llt* mum.

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