PHOSPHORESCENT AND FLUORESCENT MATERIAL

摘要

In any attempt to apply luminous material to aid military activity either in daylight or darkness many factors have to be considered if the material is to be successful. For this reason it would be appropriate for the personnel who have the responsibility of engi¬neering the use of such material to answer the following questions before a decision is made.n1. Is the luminous material to be used under conditions of darkness or under day¬light illumination? For example, is the material to be used to assist in the evacuation of a ship under conditions of power failure or is it to be used to make objects such as aircraft more visible during the day?n2. Will the material be required to be useful for only a relatively short time after activation has ceased or must it be visible for long periods? For example, emergency gear such as valve handles and switches may be required to be visible for a few minutes to an hour in case of power failure. In this case a phosphorescent paint would be entirely suitable, while such a paint would be unsatisfactory to illuminate deck gear on the weather deck of ships which were to be operated during all hours of darkness.n3. Must the shapes of luminous surfaces be accurately determined ? For Instance must letters, numerals, or directional signs be quickly and definitely legible?n4. Will color be an important consideration? This may be of importance in dif¬ferentiating items of positions.n5. What will be the state of dark adaptation of the observer's eyes? As an example, will the observer be in highly illuminated spaces and then suddenly plunged Into darkness as in the case of power failure or in the case of an officer going from the chart room to the darkened bridge?n6. Will the observation of the luminous material be made under conditions of emergency or will the observer have plenty of time to consider the situation?n7. Will the observation of the material be made against a sea, sky, or land back¬ground? This is particularly important where the luminous material is used to make aircraft more visible in daylight or where it is used to assist such military activity as amphibious landings.n8. To what type of environment will the material be exposed? An examination should be made of the position on the ship, humidity, exposure to light, temperature, and exposure to mechanical shock and vibration.