![<?echo $_SERVER['SERVER_NAME'];?>](/template/twentyseventeen/skin/images/header.jpg)
In daily life, we can also feel that when viewing the same item under different light sources or environments, the color of the items presented in our eyes will be more or less biased because different light sources have different spectral characteristics. When the same object is illuminated, different colors appear.
Similar situations can occur when color management is performed in a printing house. For example, although the quality inspector has carefully compared the color of the product, the product will be received by the customer when it is sent to the customer. The company may be subject to returns or customer claims, and the company's reputation is naturally affected.
To solve this problem effectively, the easiest way is to verify the color of the product under the same light source and controllable conditions, such as the commonly used fluorescent lamp CIED65 (ie 6500K color temperature), otherwise all evaluation is meaningless. To achieve this, it is no more than using the most commonly used standard pair of color sources.
As a customer service personnel who provide quality inspection equipment manufacturers for printing companies, I contact the quality inspection department of the printing house all the year round. The following are the conditions for how to carry out the standard color and the requirements.
Light source standard
1. Use fluorescent lamp D65
The fine color discrimination work in industrial production requires the illumination source to have a true solar spectrum distribution (including ultraviolet radiation and spectral radiation), and the fluorescent lamp D65 approved by the International Commission on Illumination (CIE) can perfectly simulate real daylight.
2. Light source characteristics
The illumination range of the light source ranges from 750 to 3200 lux (Lux), the color rendering index is >90, and the uniformity is >80%.
3. Requirements for background color
Obvious color is a subjective sensation, so comparing colors in different backgrounds can produce different results. Therefore, all background colors are specified as NeutralGrey with a Munsell brightness value of 6-8.
4. Requirements for environmental factors when distinguishing colors
Try to block all the extraneous light that may strike the detector. If the window is in the field of view, it should also be fitted with gray curtains, so it is ideal to distinguish colors in the darkroom.
5. Record the usage time of standard lamps
All standard light sources are made up of lamps, and the lamp manufacturer also states that its products operate for a certain period of time, so an accurate time recorder is required. Usually these lamps have to be replaced after a certain amount of time.
6. Arrangement position of the lamp
There is no specific requirement for the arrangement of the lamps, but the arrangement position must have a uniform light source in the light box, and must not be lateral to an area.
Correct use of standard light sources
Observation angle
The above is the necessary equipment for the standard light source, but the viewing angle will also directly affect the color discrimination results. According to international standards, only two observation angles can be used:
A.0° light source, 45° observation (0°/45°), that is, the light source is irradiated on the printed matter at an incident angle of 0° (vertical), and the observer observes the printed matter at an angle of 45°.
B.45° light source, 0° observation (45°/0°) using a specific 45° inclined table (45°FixedAngleTable), the light source is illuminated on the printed matter at an angle of 45°, and the observer is observed at 0° (vertical) ) Observe the printed matter.
2. Placement of printed matter
Regardless of which of the above observation methods is used, the printed matter should be placed as far as possible in the middle of the light source to reduce the influence of the external light source. Most importantly, when you need to compare the color of two or more items, try not to overlap them, it is best to discharge them under the light source.
Article source address: http://
A blackboard (also known as a chalkboard) is a reusable writing surface on which text or drawings are made with sticks of calcium sulphate or calcium carbonate, known, when used for this purpose, as chalk. Blackboards were originally made of smooth, thin sheets of black or dark grey slate stone.
A blackboard can simply be a board painted with a dark matte paint (usually black, occasionally dark green).Matte black plastic sign material (known as closed-cell PVC foamboard) is also used to create custom chalkboard art.Blackboards on an A-frame are used by restaurants and bars to advertise daily specials.
A more modern variation consists of a coiled sheet of plastic drawn across two parallel rollers, which can be scrolled to create additional writing space while saving what has been written. The highest grade blackboards are made of a rougher version porcelain enamelled steel (black, green, blue or sometimes other colours). Porcelain is very hard wearing, and blackboards made of porcelain usually last 10–20 years in intensive use.
Lecture theatres may contain a number of blackboards in a grid arrangement.The lecturer then moves boards into reach for writing and then moves them out of reach, allowing a large amount of material to be shown simultaneously.
The chalk marks can be easily wiped off with a damp cloth, a sponge or a special blackboard eraser usually consisting of a block of wood covered by a felt pad. However, chalk marks made on some types of wet blackboard can be difficult to remove. Blackboard manufacturers often advise that a new or newly resurfaced blackboard be completely covered using the side of a stick of chalk and then that chalk brushed off as normal to prepare it for use.
Hanging Chalkboard,Custom Chalkboard,Portable Chalkboard,Wood Framed Chalkboard
Jinan Tri-Tiger Technology Development Co., Ltd , https://www.jinanfurniture.com