DEFINITION
MODEL 1200 SERIES
Model 1200 series consists of two basic types of retroreflectometers for the measurement of raised or recessed pavement markers (RPMs) in the field, laboratory or on the production line.
The Model 1200C
Is a battery operated instrument which can be used for field measurements of RPMs. It can also be used to assess the quality of new markers before they are placed on the pavement.
The Model 1200B
Is intended as a quality control instrument on the production line. It uses a long-life tungsten-halogen lamp and a 110/220VAC supply so continuous measurements can be made. Various configurations of the 1200B can be provided to the customer depending on the production requirements.
Some configurations supplied in the past have been a seven or eight position track (manual), an additional cover and orientation of the display for operator ease and a special meter to allow data recording via RS232C serial communication to software data logging systems.
CALIBRATION
The calibration of this Retroreflectometers is achieved through comparison against a known reference RPM.
Power and lamp switches turn on the projection lamp and the photopically corrected solid state detector measures the retroreflected light.
The light source is projected to a collimating mirror which transforms the diverging light rays to parallel rays simulating driving conditions.
Retroflected light is collected in the same manner.
The display consists nominally of a 4-1/2 digit liquid crystal display which when properly calibrated against the reference standard will measure RPM's to a precision of 0.01 candelas per foot candle or (1 mcd/lux).
The lamp switch in the 1200C is operated by the thumb when measuring and is normally off to conserve power
The model 1200C option 1 is an attachment which allows new RPM's to be measured for specification conformance at entrance angles of -- 20i, 01, +20i (left and right).
The raised pavement marker is placed on a rotating table set to the desired angle and the model 1200C is placed over the sample and measured.
GEOMETRY
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GEOMETRY |
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Observation Angle |
0.2i |
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Entrance Angle |
0I (- 20I with option 1) |
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Light source angular subtense |
0.1i |
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Receptor Angular subtense |
0.1i |
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Measurement area |
5 x 1 inches (12 x 2.5cm) |
PHYSICAL PARAMETERS
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Model 1200C |
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Size without handle |
21 inches (53.3cms)x 6.0 x 6.0 (15x15cm) |
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Weight |
16Lbs (7,3kg) 28 Lbs with case (12.7 kg) |
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Temperature range |
0 -50iC |
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Humidity |
5.90% |
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0-95% Non-condensing |
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CALIBRATION |
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Reference standards |
White, yellow, red RPMS |
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ELECTRICAL CHARACTERISTICS
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MODEL 1200C |
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Measurement range |
.01 - 199 cd/fc (1 - 19999 mcd/lx) |
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Resolution |
4 - 1/2 digit LCD |
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Controls |
Zero (dark), calibrate, momentary light switch |
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Detector/ light source |
Silicon photodiode with photopic filter combined with light source at CIE illuminant A (2856K) |
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Power supply |
Rechargeable batterry 12 VDC with recharger for 110 VAC or 220 VAC |
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Low battery indicator |
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MODEL 1200B
Power supply 110/220 VAC
Continuous lamp switch, long life tungsten halogen lamp |
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