Quick Links

© Safe Glow® Corporation 2012

Exit Signs

Emergency Lighting

Custom Products

Performance

Reports

Photoluminescent Performance Testing

The widely accepted UL 924 standard for photoluminescent exit signs includes many important specifications and considerations for the color, size, character spacing and legibility of exit signs. However, it does not specify a minimum level of photoluminescent performance or glow, so naturally there exists a wide variance in performance between UL 924 listed products.

Which is why at Safe Glow®, we don't just talk about manufacturing the brightest photoluminescent products on the market, we go the extra mile and test our products as well as the competition’s and post the results to our web site so that consumers can make informed decisions that are based on accurate, measurable criteria - not just marketing claims or doctored photos.  (Click to view our testing methodology)

Photoluminescent Performance Reports

Click on the charts below to view full screen.

Safe Glow vs. SafePassage Inc. 50 ft Exit Sign

Test: UL test criteria, fluorescent bulb

The Safe Glow Exit Sign displays 31% more initial brightness than the SafePassage Inc. sign, a margin that increases to 50% in 5 minutes and 67% in just 30 minutes, reaching a maximum of 74% brighter at the 2 hour mark.

Safe Glow vs. Jessup® Manufacturing, Glo Brite® Ecō Exit™

Test: UL test criteria, fluorescent bulb

The Safe Glow Exit sign is on average 35% brighter than the Jessup eco exit during the critical first 60 minutes of an emergency and exhibits a peak brightness advantage of 50% at the 2 hour mark.

Safe Glow 5 fc vs. 10 fc, Photoluminescent performance

Test: 5 fc and 10 fc charge, fluorescent bulb for 60 minutes

This test simply demonstrates how photoluminescent performance changes as the charge level is increased - highlighting the need for standard testing procedures.

Safe Glow Emergence Light Performance

Test: Fluorescent fixture, 8 ft. above the floor

The Safe Glow Emergency Lights provides a fail-safe emergency light source that delivers a soft green glow roughly the equivalent of moonlight for more than 30 minutes.

Safe Glow Low-level Path / Door Frame Marker Performance

Test: ASTM E2072-10 test criteria 1 fc charge, fluorescent bulb

The Safe Glow LPM exceeds the ASTM performance requirement by more than 260% at the 10 minute mark, a margin that grows to more than 450 % at the 60 minute mark.

Safe Glow SafetyTread™ Performance

Test: ASTM E2072-10 test criteria 1 fc charge, fluorescent bulb

The Safe Glow SafetyTread sexceed the ASTM performance requirement by more than 110% at the 10 minute mark, a margin that grows to more than 250 % at the 60 minute mark.

Safe Glow Exit Sign Photoluminescent Performance

Test: UL 924 criteria (5 fc charge for 60 minutes)

Safe Glow's exit signs exhibit the industries brightest photoluminescent performance and are unsurpassed in the 50 foot visibility category.

Why We Test

While UL 924 does not establish a minimum photoluminescent performance level for exit signs, it does establish a minimum light level (charge source) that must be present on the face of the signs. The UL 924 standard specifies a charge light level of 5 foot-candles of unfiltered illumination (fluorescent, metal halide or mercury vapor) on the face of the sign during periods of building occupancy.

As photoluminescent performance is directly correlated to the charge level that it receives (more light means brighter glow), we felt it was important to conduct our comparative testing using the established UL 924 minimum of 5 foot-candles of light.

Testing Methodology

When testing photoluminescent performance we apply a scientific methodology designed to create a repeatable set of results so that others can conduct these tests and achieve similar results.

• All photoluminescent products are placed in total darkness for 48 hours prior to test commencement to assure that any meaningful level of charge has been eliminated from the photoluminescent material
• All tests are performed in our specially constructed test chamber that provides a tightly controlled environment. The test chamber is equipped with a fluorescent fixture that provides the charge light source, a vent system to control air temperature, an adjustable light screen to control the light level and two DIN class A photometric detectors that provide highly accurate measurement of both the charge luminance (foot-candles) and discharge or glow luminance (millicandela)
• The charge light source is calibrated to 5 foot-candles of luminance using a Gigahertz-Optik X1 optometer with a VL-3701 (DIN class A) illuminance detector. During testing the light level is maintained within a tolerance of less than +/-  .1 foot-candle (2%) - the resulting accuracy is well beyond UL test procedures
• The product to be tested is inserted into the test chamber with the photoluminescent surface facing the charge light source (90 degree angle) and the 60-minute timer is started
• Throughout the test period the charge light level is continuously monitored using the VL-3701 illuminance detector, readings are taken and recorded at 1 minute increments during the 60-minute charge phase to assure accurate and consistent light levels are maintained
• During the test period the internal temperature of the test chamber is monitored and maintained at 75 to 80 degrees Fahrenheit.  Consistent temperature is important as the charge light source and photoluminescent performance are both affected by temperature variations
• At the end of the 60-minute charge phase the charge light source is switched off and the photoluminescent performance testing phase begins. Using a Gigahertz-Optik X1 optometer with a PD-9310A (DIN class A) high sensitivity illuminance detector. The PD-9310 detector is placed directly on the surface of the object to be measured
• For all testing the X1 optometer is connected via USB to a Windows XP server running the Gigahertz-Optik OS-X1 remote control software. The OS-X1 software logs the both the charge light level and photoluminescent performance readings at one minute intervals for the duration of the test
• GTI 6500K ColorMatcher D65 fluorescent lamps are used as the charge light source in the test chamber. The GTI lamp was selected for its tight adherence to the CIE standard that specifies the aim points and allowable tolerance for simulated daylight sources (ColorMatcher data sheet). We chose not to use the commercially available "Cool White" fluorescent lamps for our testing due to the wide variance in color temperature and spectral power distribution that they exhibit - making accurate and repeatable testing with multiple bulbs/manufactures virtually impossible

Complete and detailed test results (containing all of the raw data) are available upon request. Simply complete the contact form on the Contact page and we will be happy to send you the requested file.