Accurate and Traceable Retroreflectivity Measurements

Highway statistics indicate that you are three times more likely to have an auto accident at night versus during the day. While circumstances such as driver fatigue, driver’s age and adverse weather conditions are contributing factors, the nighttime visibility of traffic control signs and pavement markings also play a major role in the increased risk. Led by the Federal Highway Administration’s (FHWA) http://safety.fhwa.dot.gov/roadway_dept/retro/ movement towards retroreflectivity guidelines, more government agencies are adopting sign and pavement marking performance standards. As a result, the reliability of the instruments that measure performance becomes crucial.

DELTA Instruments were developed in order to objectively monitor the optical performance of today’s traffic control signs and markings. Located in Denmark, DELTA is a world leader in the development of photometric instruments to measure the retroreflectivity of pavement markings and sign sheeting.

Flint is the exclusive distributor in the United States, Canada and Latin America for the following DELTA instruments:

LTL-X Retroreflectometer

Traceable and Verifiable

DELTA’s photometric instruments are engineered to the industry’s most-exacting tolerances. Each instrument is calibrated and traceable to an accredited national standards laboratory through an ISO 17025 certified testing and calibration laboratory. A certificate of conformance and traceability is supplied with each DELTA instrument.

Traceability has several very important advantages:

Reproducibility – traceability to a single national standard helps to ensure that all DELTA instruments calibrated to that standard will get the same measurements on a given spot within +/-5%.

Repeatability – The Certificate of Conformance and Traceability that is included with every DELTA instrument ensures that the readings taken with a DELTA instrument are within +/-2% in repeatability.

Tort Liability – Documented traceability provides credibility to performance measurements collected by the instrument that may be questions during potential liability cases.

Technical Notes from DELTA
Work on Reflection Properties at DELTA
Reflection and Retroreflection
Measurement of Reflection and Retroreflection
What To Know About Marking Reflectometers
Portable Retroreflectometers and Structured Pavement Markings
Road Markings: Choose the Right Type of Retroreflectometer