Flush or Semi Flush?

Flush mount and semi-flush mount lighting fixtures are integral components in lighting design, adding interest and depth while providing ambient illumination and decorative lighting effects to hallways, bedrooms and bathrooms.

The difference between a flush and semi-flush light fixture is that a flush fixture fits snugly to the ceiling, while a semi-flush fixture is suspended, leaving a small gap between the ceiling and fixture.  Opting for a flush or semi-flush light fixture is based upon taste and proportional considerations, but a few standard rules apply:

♦ Semi-flush—Somewhere in between the chandelier and standard ceiling fixture, the semi-flush fixture shines with distinction.  Taking up just the right amount of space with the power to attract desired attention, the latest semi-flush light fixtures provide superb illumination with artistic excellence.

♦  Semi-flush fixtures provide an added benefit: the small gap allows for double the illumination with indirect uplight rebounding off the ceiling and downlight emitted directly from the fixture.

♦  Flush fixtures—Most often employed in homes with standard 7-foot ceilings to provide general illumination for bedrooms, bathrooms, foyers and hallways.

Novel compositions and unique finishes are available at a variety of price points and are being featured from top lighting vendors around the world, making it easier than ever to find ceiling light fixtures in keeping with your budget and style requirements.

Corbett Lighting offers outstanding flush and semi-flush lighting designs:

-CQ33 “Cirque” Semi- Flush Fixture

-120-33 “Karma” Flushmount Fixture

A Programmable Logic Controller (PLC) receives information from one or more inputs. This semiconductor control device processes the information based on a software program. Finally, it sends an output control signal. The microprocessor based control system performs functions such as timing, logic, sequencing and others. The PLC follows instructions from an operator-defined program.

These intelligent systems provide reliable, high-speed monitoring and control of processes in automated applications. In addition, they are easy to program and configure.

Once the program updates the output, the CPU starts over and the cycle repeats again. The cycle depends on the number of inputs, outputs, and size of the program, while the action will depend on the inputs coming from a variety of sensors.

The input sensors include components such as switches, proximity sensors, photoelectric sensors, pressure switches, level switches, encoders and temperature sensors, while the output devices include actuators, relays, switches, and many more.

PLCs rely on software programs that help them in making the necessary decisions. The PLCs are programmed through a variety of tools, which may differ in ease of use, appearance, and complexity. The most commonly used PLC programming language is Ladder Logic, a graphical software that uses common electrical symbols. Other languages include Function Block Diagram (FBD), Sequential Function Chart (SFC) and Structured Text (ST).

The programming is done on the device such as a computer or handheld device after which it is transferred to the PLC memory using a communication interface.

Selecting a suitable PLC that will address your current and future needs can be a challenge, especially with the large number of different PLCs on the market today. The available PLCs have varying capabilities, physical sizes, complexity, cost, power requirements, scalability and other parameters. Therefore, it is necessary to determine the correct programmable logic controller for your specific application. Special systems can be designed for use in harsh environments.

The Programmable Logic Controller has revolutionized and simplified controls in automation and industrial applications. PLCs are easy to install, wire, program and modify to suit changing application requirements. These control systems are usually available in a wide range of sizes that ensure finding exactly what you need for any application.

Museums have a hard line to walk, exhibiting items for public education and enjoyment while protecting those same collections from damage. Today’s museum also carry the additional weight of safeguarding the future of the environment – as well as their financial future – against the dangers of unnecessary energy consumption. What advancements have been made in preservation lighting technology to help accomplish these goals?

Light, including all three types: ultraviolet (UV), infrared, and visible light, causes permanent and irreversible damage to museum pieces. Cumulative and dependent on the intensity and duration of exposure, light affects chemical composition, physical structure, and, the appearance of a collection. There is no conservation treatment that can repair it. Light damage is forever.

Only complete darkness ensures conservation, since exposure to light in any form naturally breaks down items. However, keeping pieces locked away in the dark defeats the mission of the museum – sharing those works with the public. It is thus a museum’s dilemma to find a suitable solution that balances the best of both worlds, in addition to considering energy costs and the environmental impact of its lighting selection.  

In your search for preservation lighting, you will find that a great deal of lighting solutions involve UV (ultraviolet light), the most energetic and destructive form of light. These include natural light, fluorescents, HID, and tungsten halogen lighting. Fortunately, the effects of UV can be controlled with simple filters, offering a greater variety of lighting options. UV filters are hard plastic tubes or soft sleeves wrapped around bulbs/light sources, which filter and block up to 98 percent of UV light, preventing its damaging effects. NOTE: UV filters lose efficiency over time and must be replaced every eight-10 years.

Specific, detailed recommendations for preservation lighting levels based on your collection type can be found from various sources, including the Library of Congress, National Park Service, UNESCO, and more.