HP Color 9850mfp Service Manual - Page 41

I OUTLINE hp Color 9850mfp OUTLINE OF SYSTEM Therefore, paper storage and handling are as important as the paper-making process itself. Paper storage environmental conditions directly affect the feed operation. Users should not purchase more paper than can easily be used in a short time (about three months). Paper stored for long periods might experience heat and moisture extremes, which can cause damage. Planning is important to prevent damage to a large supply of paper. Unopened paper in sealed packages can remain stable for several months before use. Opened packages of paper have more potential for environmental damage, especially if they are not wrapped with a moisture-proof barrier. The paper storage environment should be correctly maintained to ensure optimum printer performance. The required condition is 20 to 24 C (68 to 75 F), with a relative humidity of 45 percent to 55 percent. The following guidelines should be helpful when evaluating the paper s storage environment: z Paper should be stored at or near room temperature, laying flat. Do not store packages vertically. z The air should not be too dry or too humid (because of the hygroscopic properties of paper). z The best way to store an opened package of paper is to rewrap it tightly in its moisture-proof wrapping. If the printer environment is subject to extremes, unwrap only the amount of paper to be used during the day's operation to prevent unwanted moisture changes. Testing media specifications The following tests describe ways to evaluate media with respect to the specifications listed in this manual, and the HP LaserJet Printer Family Print Media Guide. See Media assessment tools and suppliers on page 1-19 for help obtaining the tools that are needed to perform these tests. Basis weight field test The basis weight should be indicated on the package label. If the label is not available, a simple field test can determine the basis weight of paper. The basis weight of paper is equal to the weight of 2,000 sheets of paper, or about four full packages. Weigh a full package on a postal scale and then multiply that weight by four. Or weigh 10 sheets of paper, divide that weight by 10, multiply by 2,000, and then divide by 16. Example 10 sheets weigh 1.6 ounces 1 0 0.16 ounce x 2,000 = 320 ounces 320 ounces 1 6 ounce/lb = 20 lb paper (letter only) Table 15. Determining basis weight of paper Amount Formula Four packages weight = basis weight One package weight x 4 = basis weight 10 sheets (weight divided by 10) x 2,000 and then divided by 16 = basis weight Metric sizes For metric-size paper (A4), use the following method to determine basis weight. Take 16 sheets of A4 paper and weigh them. One square meter of paper contains approximately 16 A4 size sheets. Compare this weight to the appropriate weight in the paper weight equivalence table. 1-15