832.02 Optically -Programmed Adjustable Traffic Signal Heads
OPTICALLY -PROGRAMMED ADJUSTABLE TRAFFIC SIGNAL HEADS
832.01 Description
This work consists of providing and installing optically -programmed adjustable t raffic signal heads and lamps on supports.
832.02 Materials
Provide optically -programmed adjustable traffic signals capable of allowing optical determination of the visibility zone of the indication. Ensure the signal does not require hoods or louvers. P rovide for projected indications selectively visible or veiled within 15° of the optical axis. Ensure the indications emanate from a single section. Ensure external illumination does not provide indications. Prevent one light unit from illuminating a se cond unit.
A.Optical System Provide a lamp with the following characteristics: 75 W, 120 V (AC), Three prong, Sealed beam, With an integral reflector with stippled cover, and With an average life rating of at least 6,000 hr. Provide a lamp collar, includi ng specular inner surface, that couples the lamp to the diffusing element. The diffusing element may be discrete or integral with the convex surface of the optical limiter. Provide an optical limiter made of heat -resistant glass with an accessible imaging surface at focus on the optical axis for objects from 900 ft to 1,200 ft [275 m to 365 m] away. Provide an optical limiter that allows the application of a veiling mask, determined by the desired visibility zone. Provide a high resolution planar incremental lens for the objective lens; hermetica lly sealed within a flat lamina te of weather resistant acrylic or an equivalent approved by the Resident Engineer. Ensure the lens has a symmetrical outline and can rotate 90° about the axis without displa cing the primary image. Provide an optical system that accommodates projection from a single section of diverse selected indicia to separate portions of the roadway so one indication is visible at a time. Provide the projected indication in accordance wit h ITE chromaticity standards.
B.Electrical Provide a separately accessible housing and integral lamp support for the lamp fixture, with indexed ceramic socket, and self -aligning, quick release lamp retainer. Electrically connect the case OPTICALLY -PROGRAMMED ADJUSTABLE TRAFFIC SIGNAL HEADS 832.05 and lamp housing with an interlock assembly, which disconnects from the lamp holder when opened. In each signal section, include a covered terminal block for clip or screw attachment of lead wires. Interconnect sections with concealed copper No. 18 AWG, stranded and cod ed wires, to enable field connection.
C.Photo Controls In each signal section, include an integral way to regulate its intensity between limits as a function of background illumination. Ensure that the lamp intensity is at least 97 percent of uncontrolle d intensity at 10,760 lx, and reduces from 13 percent to 17 percent of maximum at less than 11 lx. Ensure response is proportional and instantaneous when illumination increases to 10,760 lx, and damped for decreases from 10,760 lx. Provide an intensity co ntroller with an integrated, directional light sensing and regulating device interposed between the lamp and line wires. Ensure that the intensity controller is compatible with 60 Hz input and is responsive from 105 V to 135 V. The Contractor may phase -control the output for a controller with terminal impedance of 1,200 Ω open circuit and a corresponding holding current.
832.03 Equipment — Vacant
832.04 Construction Methods
Provide die cast aluminum parts in accordance with ITE alloy and tensile requirements and with a chromate preparatory treatment. Finish the exterior of the signal case, lamp housing, and mounting flanges with a high quality prime baked enamel and finish paint. Make the lens holder and case interior optical flat black. Predri ll the signal case and lens holder for backplates and visors. Use stainless steel hinges and latch pins. Seal access openings with weather resistant rubber gaskets. Mount the signal to standard 1½ in [38 mm] fittings as a single section, as a multiple se ction face, or combined with other signals. Provide the signal section with an adjustable connection enabling incremental tilting from 0° to 20° below horizontal while maintaining a common vertical axis through couplers and mounting. Ensure that the moun ting attachment allows external adjustment in 5° increments about the mounting axis. Provide a mountable signal capable of being serviced with standard tools. Ensure that attachments fasten to mounting surfaces without affecting water and light integrity of the signal. Install, direct, and veil the signal in accordance with manufacturer’s instructions. Mask signal sections with manufacturer -recommended materials.
832.05 Method of Measuremen T — Vacant
833.06 Traffic Signal Backplates
832.06 Basis of Payment
The Department will pay for each pay item at the contract unit price per the specified pay unit as follows: Pay Item: Pay Unit: OPTICALLY -PROGRAMMED ADJUSTABLE TRAFFIC SIGNAL HEADS Each Include the cost of masking, wiring, and hardware in the contract unit price for Optically Programmed Adjustable Traffic Signal Heads . SECTION 833 TRAFFIC SIGNAL BACKPLATES
833.01 Description
This work consists of providing and installing backplates to traffic signal heads.
833.02 Materials
Provide backplates in accordance with Section 740, "Traffic Signal Backplates."
833.03 Equipment — Vacant
833.04 Construction Methods
Provide metal or one piece non -metal backplates. The Department will allow the use of two or three piece non -metal backplates for S -19 signal heads. Provide a 2” border of retroreflective sheeting, as near to the outer edge of the backplate as permitted by the contours of the backplate. Secure the backplate to the traffic signal heads with non -corrosive machine screws, washers, and lock nuts as shown on the Plans. Connect the pieces of multi -piece backplates together according to the specifications of the manufacturer.
833.05 Method of Measuremen T — Vacant
833.06 Basis of Payment
The Department wil l pay for each item at the contract unit price per the specified pay unit as follows: Pay Item: Pay Unit: BACKPLATES Each
Source: Oklahoma Standard Specifications for Highway Construction, 2019 Edition. Pages 864–865 of 935.