Lighting recommended levels

A designer of lighting systems was called in. He recommended surface mounted fluorescent fixtures, which he considered more efficient than the recessed ones. The laboratory operator scanned all work areas with a light meter after the job was completed. The light was even and well within recommended levels. Fiirther-more, there were never any problems with the fixtures themselves, except for an occasional change of tubes. 

A set of tables, based on this formula, has been produced by the Society of Light and Lighting for a range of situations, types of luminaire, etc., and these should be referred to for specific advice. Figures above the recommended levels for a given location may lead to visual discomfort. 

To be able to carry out any work effectively and accurately proper and appropriate lighting is essential. The eye reacts to strong or bright light such ttiat areas of shadow or darkness are not seen in as much detail if at all. With all work situations suitable and sufficient lighting that enables the eye to see all the facets of the work and the surrounding area is necessary. Recommended levels of illuminance for various locaHons and tasks are give in section 3.7.6. 

Potassium is determined in the acetic acid as well as the lactic acid extract. The potassium values for biologically managed fields lie between 100 and 200 mg K kg soil, and are less than those recommended for conventional agriculture. Light soils normally have low values, and clay soils, which bind more potassium, have higher K levels. Potash fixation is also assessed according to Schlichting and Blume (1951, p. 84). 

Iodide or iodate are used to iodize salt. The level of salt iodization depends on per capita salt consumption, moisture, light, heat, and contaminants. The recommended daily iodine requirements are 50 pg for infants, 90 pg for children (2-6 yrs), 120 pg for schoolchildren (7-12 yrs), 150 pg for adults and 200 pg for pregnant and lactating women. 

Jing Mi and Gan Cao enter the Spleen meridian and can protect the Stomach and Spleen from the cold herbs that clear heat at the Qi level. They can also tonify the Spleen-Qi and thereby strengthen body resistance. Porridge made from Jing Mi is light and easily digested. It is recommended as a food in the recovery period of a febrile disease. 

Atomic absorption is used for the determination of ppm levels of metals. It is not normally used for the analysis of the light elements such as H, C, N, 0, P and S, halogens, and noble gases. Higher concentrations can be determined by prior dilution of the sample. AA is not recommended if a large number of elements are to be measured in a single sample. 

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