NALMCO SPONSORS MAINTENANCE STUDY

validate the method with field measurements, identify any relationship between age and average brightness, and gain insight regarding the incidence of exit signs no longer satisfying minimum brightness requirements.

Specific tasks to be completed by the research team include:

Literature review: The researchers will review all existing studies related to factors that make luminous signage detectable, identifiable and legible. The review will validate criteria for brightness, uniformity and contrast under critical conditions. Best practices, specification guide and related standards will be reviewed. This task will produce photometric criteria against which field measurements can be compared.

Concurrently, the researchers will interview experts to identify industry priorities and common practice for selecting, installing and maintaining exit signs. The National Fire Protection Association (NFPA) and the Fire Protection Research Foundation (FPRF) will be invited to contribute information about key issues related to the use of exit signs under emergency situations.

Field measurement procedure: The researchers will acquire several types of green and red exit signs and evaluate a range of methods to test sign brightness. These may include spot measurements at the sign using a portable luminance meter or digital imaging and also measurements at a known distance. These methods will be compared for simplicity, repeatability, accuracy, and cost. This task will produce a procedure for measuring exit signs in the field.

Field measurements: The researchers will conduct field measurements of exit signs installed in buildings in at least two locations. As much information as possible about exit sign operating age will be documented. The measurements will target about 100 to 120 signs, focusing on panel-face signs using red or green LEDs. This task will produce a large set of data with which to test the hypothesis.

Technical analysis: The researchers will estimate the number of exit signs with potentially insufficient brightness and relate that to the age of the sign. This is the ultimate test of the hypothesis that the greater proportion of older exit signs will have insufficient brightness. If the hypothesis is confirmed, the researchers will compare expected and actual lumen depreciation. If the hypothesis is not confirmed, the researchers hope to gain an estimate of the portion of exit signs that produce insufficient brightness, regardless of age.

Present the results: The researchers will host a roundtable of relevant stakeholders, including NALMCO, to share project findings and discuss next steps. These may include: including field measurements in exit sign evaluation programs, potential changes to existing standards, and education of building owners regarding if, how, and when to evaluate exit signs. A report will be produced.

The researchers anticipate that this will be an initial study to develop a field measurement method and test the hypothesis. They expect the results will support a larger study that will include more applications and locations. The ultimate goal is to get a handle on the scope of the problem should it exist and produce actionable guidance for maintenance and replacement of exit signs.

This is a significant study in the industry, as it could result in revision of lighting maintenance practices, possibly affect future development of life/safety codes, and produce opportunities for lighting management companies.

Craig DiLouie, CLCP, LC, principal of ZING Communications, Inc., is a consultant, analyst and reporter specializing in the lighting and electrical industries, and a regular contributor to LM&M. You may contact Craig at cdilouie@zinginc.com.