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Delineator Reflectors are purchased throughout the year, and samples are obtained from each shipment. On the left is a picture of our ESNA Reflex Photometer tube, which is used to determine the delineator’s measured ability to reflect light. This ability is referred to as Specific Intensity.

The delineator's Specific Intensity is measured at both the 3-foot and 10-foot stations and with an Entrance Angle of 0 and 20 degrees at each stations. 25 delineators chosen at random are measured at both stations for a total of 50 delineators tested for each color received in the shipment. The Specific Intensity is reported as the average C.P./Ft.C. (Candle Power per Foot Candle) per 25 delineators per station sorted by color. The delineator manufacturers produce their product with a Specific Intensity that far exceeds the Department of Road’s requirements, and in time, delineator reflectors may be placed on the Approved Products List.

These are the calibration and readings display units for the photometer tube. A standard of matching color with a known Specific Intensity is calibrated with these controls. Sampled delineators from the shipment are then run using the standard for reference.

Also pictured are delineators representing the full range of colors that we sample and test.

Delineator Reflectors are measured for their Reflective Area, which is reported in square inches. They are also checked for type of lens material, type of front and rear surfacing, and the lens segments are counted. The mounting hole diameter is measured and the grommet is verified to be non-ferrous. To make sure the delineators can withstand the rigors of Nebraska weather, a Heat Resistance test is done on three delineators of each sampled color. The delineators are placed into an oven at 65 degrees Celsius for 4 hours and are then tested for Specific Intensity again. The oven-treated delineators are still required to exceed the minimum C.P./Ft.C. requirement.

The last remaining test is the Seal Test. Fifty delineators of each sampled color are placed into the vacuum-and-bucket assembly pictured here. The delineators are covered in water and then five lbs. of vacuum is applied for five minutes. The vacuum is turned off and the delineators are left to “soak” for another five minutes. They are then removed from the bucket, dried off, and visually observed for any invasive water. This tells us how well the hermetic seal will hold up to several years of rain, ice, and snow. Once moisture gets into a delineator, its reflective capabilities are greatly reduced. Only one failure of the hermetic seal per fifty delineators of any one color is allowed.