the panel surface for 5 minutes. At the end of the 5 minute period, check the distance of peeling. Failure of any one specimen shall constitute failure of the test. (e) Colorfastness One of the specimens prepared and subjected to accelerated weathering specified in 633.06(j) shall be used to test for colorfastness. Wet out the specimen with a mild detergent and water solution and compare it visually with a similarly treated unexposed specimen under natural (North sky) daylight or artificial daylight having a color temperature of 7500K. The colorfastness shall be evaluated as follows: Excellent-No appreciable change in color Good-Perceptible but no appreciable change in color Appreciable change in color means a change that is immediately noticeable in comparing the exposed specimen with the original comparison specimen. If closer inspection or a change of angle of light is required to make apparent a slight change in color, the change is not appreciable. The reflective material must show "good" colorfastness or better. (f) Fungus Resistance For use in areas where fungus growth may be a problem and if specified by the Engineer, fungus resistance shall be determined as specified herein. After inoculation with the test organism, Aspergillus niger, and incubation for 14 days, the reflective material shall show no appreciable formation of fungus growth. Any formation of fungus growth shall be non-injurious to the reflective material and shall be removable by wiping with a soft cloth. After completion of the incubation and after being wiped clean, the reflective material shall retain the full reflective intensity values as specified in Tables III, IV, V, or VI of subsection 633.06(c). (1) Test Organism The test organism used in this test shall be Aspergillus niger, ATCC No. 6275. (This organism may be obtained upon request from the American Ty me Culture Collection (ATCC), 12301 Parklawn Drive, Rockville, Maryland 20852, or Mycology Laboratory, PRL, U.S. Army Natick Laboratories, Natick, Massachusetts 01760). Cultures of this organism shall be carefully maintained on a potato-dextrose agar medium and promptly renewed if there is evidence of contamination. The stock cultures may be kept for not more than 4 months in a refrigerator at a temperature from 37.4° to 50°F. Subcultures incubated at 82.4° to 86°F for 10 to 14 days shall be used in preparing the inoculum. The pH shall be 5.5 to 6.5: if otherwise, adjust to that range with HC1 or NaOH. After mixing, the ingredients shall be sterilized by autoclaving for 15 minutes at 15 p.s.i. at 120°C. Under sterile conditions, the medium shall be poured into six 150 mm by 20 mm petri dishes, about 65 ml per dish, and allowed to harden. (3) Inoculum Add about 10 ml of sterile, distilled water containing about 0.005 percent of nontoxic wetting agent to a subculture (10 to 14 days old) of the test organism in a ripe, fruiting condition. The spores shall be forced into suspension with a sterile camel's hair brush (or other suitable means) and diluted to 100 ml with sterile, distilled water. (4) Preparation of Specimens Cut three 3 inch by 3 inch specimens from the sample and apply to test panels with the reflective surface up. Completely immerse the test specimens in a leaching tank of continuously flowing water for 24 hours and then remove and dry. The leaching tank shall be large enough to hold an account of water weighing not less than 50 times the weight of the specimens. The water entering the tank shall not fall directly on the specimens and shall flow at a rate of 5 to 10 liters per hour. The pH of the water shall be in the range of 6.0 to 8.0. (5) Inoculation Under aseptic conditions, dip each specimen in 70 percent ethanol for a few seconds, rinse in distilled water, and place firmly on the surface of the solidified agar medium contained in the petri dishes. Place specimens with the reflective surface facing up, one specimen to each dish. With a sterile pipette, distribute 1.0 to 1.5 ml of inoculum over the surface of each specimen and the surrounding medium. (6) Incubation Period The period of incubation shall be 14 days at a temperature of 84.2° to 89.6°F and 85 to 90 percent relative humidity. (7) Control Test three control specimens of untreated, porous-grade filter paper with the specimens of the reflective material to check the viability of the inoculum. At the end of the incubation period, the controls should be covered with fungus growth. (8) Test Results Upon completion of the incubation period, examine the specimens visually for fungus growth. Wipe the specimens with a soft cloth wet with a 70 percent ethanol solution. Condition the specimens at standard conditions for 48 hours. Test the specimens in accordance with subsection (c), and when finished, attempt to remove specimen from the test panel. APPENDIX (Sample Only) These General Provisions are included as a sample informational copy only and are not to be considered as a part of these standards specifications. The Standard Forms applicable to each contract will be included in the "Invitation for Bids." 1. DEFINITIONS GENERAL PROVISIONS (a) The term "head of the agency" or "Secretary" as used herein means the Secretary, the Under Secretary, any Assistant Secretary, or any other head or assistant head of the executive or military department or other Federal agency; and the term "his duly authorized representative" means any person or persons or board (other than the Contracting (Officer) authorized to act for the head of the agency or the Secretary. (b) The term "Contracting Officer" as used herein means the person executing this contract on behalf of the Government and includes a duly appointed successor or authorized representative. 2. SPECIFICATIONS AND DRAWINGS The Contractor shall keep on the work a copy of the drawings and specifications and shall at all times give the Contracting Officer access thereto. Anything mentioned in the specifications and not shown on the drawings, or shown on the drawings and not mentioned in the specifications, shall be of like effect as if shown or mentioned in both. In case of difference between drawings and specifications, the specifications shall govern. In case of discrepancy either in the figures, in the drawings, or in the specifications, the matter shall be promptly submitted to the Contracting Officer, who shall promptly make a determination in writing. Any adjustment by the Contractor without such a determination shall be at his own risk and expense. The Contracting Officer shall furnish from time to time such detail drawings and other information as he may consider necessary, unless otherwise provided. 3. CHANGES (a) The Contracting Officer may, at any time, without notice to the sureties, by written order designated or indicated to be a change order, make any change in the work within the general scope of the contract, including but not limited to changes: (1) In the specifications (including drawings and designs); (2) In the method or manner of performance of the work; (3) In the Government-furnished facilities, equipment, materials, services, or site; or (4) Directing acceleration in the performance of the work. (b) Any other written order or an oral order (which terms as used in this paragraph (b) shall include direction, instruction, interpretation, or determination) from the Contracting Officer, which causes any such change, shall be treated as a change order under this clause, provided that the Contractor gives the Contracting Officer written notice stating the date, circumstances, and source of the order and that the Contractor regards the order as a change order. (c) Except as herein provided, no order, statement, or conduct of the Contracting Officer shall be treated as a change under this clause or entitle the Contractor to an equitable adjustment hereunder. (d) If any change under this clause causes an increase or decrease in the Contractor's cost of, or the time required for, the performance of any part of the work under this contract, whether or not changed by any order, an equitable adjustment shall be made and the contract modified in writing accordingly: Provided, however, That except for claims based on defective specifications, no claim for any change under (b) above shall be allowed for any costs incurred |