Keystone 1157 The DVS-V Test Instrument, Basic Instrument Features, Headrest, Lighting System

The DVS-V Test Instrument

The Keystone DVS-V Vision Screener represents the fifth gen- eration of electro/mechanical vision test instruments. All func- tions are under push button con- trol… for unparalleled ease and reliability of operation. Com- pletely self contained, the unit operates from standard 110-120 volt AC power. It’s light in weight, unusually compact, and can go wherever it’s needed.

Basic Instrument Features

Headrest

The test subject’s forehead should rest lightly against this specially designed strip.

Lighting System

Tests are illuminated by two long-life Daylight LED lamps

63º

that virtually assure that the lamps will never fail or need to be changed during the life of the machine.

Far Point System

Far test distances are created using single-segment, hard resin lenses. Test targets appear at the precise equivalent of twenty feet.

Optical Sensor

This exclusive accessory device assures that a test subject’s head is properly positioned in the in- strument. If it is not, the target illumination lamps will not light and no test can be conducted. This also increases energy effi- ciency and extends lamp life. If desired, the sensor can be over-

ridden using the Elliptech Hand Control.

Power Switch

The off-on power control is lo- cated on the rear of the instru- ment case.

Elliptech Control Unit

Puts test operations under push button command.

Transformer

To eliminate electrical and heat hazards, power for the DVS-V is converted to 12 volts dc. A UL- listed wall transformer is sup- plied as an integral part of the power cord.

Light and Compact

Only 10” wide, 15-1/2” long and 6-1/2” high, the DVS-V is a space saver that requires little more than a square foot of desk area. Total unit weight is less than 11 pounds.

Peripheral Vision Test

Light emitting diode target lamps between the lenses and recessed in the temple areas of the view- ing head, measure horizontal peripheral visual fields. They are positioned so eyeglass frames will not interfere with testing.

Storage Area

Aconvenient storage area, ac- cessible from the rear, is built into the base of the instrument. The control unit, transformer, and record forms may be stored there when the DVS-V is not in use.

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