The gas chromatograph should pay attention to the following factors in use:
(1) Environmental conditions The gas chromatograph does not have strict requirements on the ambient temperature. Generally, it can be operated normally at room temperature of 5 ï½ž 35 â„ƒ. However, the general requirement for the ambient humidity is 20% to 85%. In highly humid areas, when using the hydrogen flame ionization detector of some models, the insulation performance of the amplifier will be reduced due to high humidity. If you operate on a high sensitivity block, the response value will decrease. Analysts should take necessary measures if they encounter the above phenomena while using the instrument.
(2) The purity of the gas source used in the gas purity gas chromatograph must be above 99.99%. At present, many operators have not paid enough attention to the problem of different detectors requiring different gas source purity. In use, the detector may have high detection limits and unstable baseline due to insufficient gas source purity. For example, when hydrogen with a purity of 98% is used as the gas source of the hydrogen flame ionization detector, when it is used on the 104MÎ© sensitivity block of the detector, the baseline may be seriously unstable due to insufficient hydrogen purity (containing flammable gases such as methane). , As if there are peaks that never end. If the purity of the carrier gas is not high and the trace oxygen is contained, it will affect the life of the capillary column.
(3) Selection of air flow ratio For the lower hydrogen flame ionization detector, N2-H2-Air flame is required, and it should be an oxygen-enriched flame after ignition, that is, the air should be excessive to ensure that the hydrogen is completely burned, the best ratio of the three gases N2: H2 = 1: (0.85 ï½ž 1), Air: H2 = (6 ï½ž 8): 1 or greater air volume. Under this condition, the detector has high sensitivity, good stability and reliable quantitative correction factors.
Promotional Paper Bags (Gift Bags) have many varieties of different type:
Press material can be divided into: white cardboard paper, white paper bags, art paper bags, Kraft paper bags, there is a small amount of specialty paper manufacturing.
White cardboard: strong white cardboard thick, with high stiffness, bursting strength and smoothness, smooth paper, commonly used thickness is 210-300 grams of white cardboard, the most widely used is 230 white card. Printed with white cardboard paper, full color, paper texture is also very good, it is the first choice for your custom.We could customize the Gift Bags according to your request.
Copperplate paper: coated paper is characterized by a very smooth, high whiteness, smooth high gloss, also makes printed graphics, a three-dimensional picture, common thickness of 128 g -300 g, copperplate paper white cardboard and printing effects like bright colors full, compared with white cardboard, white cardboard stiffness less. This kind of Shopping Bags is easy to carry.
White Kraft paper: white Kraft paper bursting high toughness, high strength, evenness of thickness of the colored image stabilizer, according to relevant national laws and regulations restrict the use of supermarket Plastic Bags, as well as foreign countries, Europe and other countries to promote environmentally-friendly paper bag trend, and strictly control plastic pollution, plastic bags are environmentally friendly alternative to paper bags, white kraft paper market prospects. 100% pure pulp manufacturing, environmental protection, non-toxic, environmentally friendly recycling, white Kraft paper toughness good, but do not film, is widely used in the production of environmentally friendly garment bag, upscale shopping bags. Common thickness of 120 g -200 g of white kraft paper, no paper brightness and gloss, white kraft paper suitable for printing ink is not much content.
Kraft paper Tote Bag: also known as brown kraft. With high tension, high toughness, usually brownish yellow, high tear strength, burst strength and dynamic, widely used in shopping bags, envelopes and the like. Common thickness of 120 g -300 grams of brown kraft. Kraft paper is generally suitable for printing monochrome or color and the color is not complex manuscript. With respect to the white cardboard, white paper box coated paper, yellow Kraft paper lowest price.
Duplex board paper Shopping Bags: white paper is a positive white and smooth, mostly on the back of the duplex cardboard, common thickness of 250 g -350 grams of white paper side is white, one side is gray, relatively inexpensive white paper jams a little.
Black cardboard Kraft Promotional Paper Bag: as a specialty paper, double-sided black. Black cardboard paper is characterized by delicate, transparent black heart, strong thick, good folding, smooth surface, good stiffness, good tensile, high resistance to breaking and the like. Common thickness of 120 g -350 grams of black cardboard. Because black cardboard inside and outside is black, so you can not print in color pattern is only suitable for bronzing, hot silver craft. Made out of the bag is very beautiful, oh.
We have been designing and producing colorful and stylishly designed fancy Shopping Gift Paper Bags to meet our customers` requirements. We have the wide variety of Kraft Paper Bag in our stock to fulfill various needs and events such as the Paper Bags for gifts, fancy gift bags, kraft bags, paper shopping bags, Tote Bag, and wedding favor bags, etc.
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