HP Color 9850mfp Service Manual - Page 43

I OUTLINE hp Color 9850mfp OUTLINE OF SYSTEM Caliper field test The specified caliper differs according to the type of media used. Caliper can be measured in the field by using a micrometer. CAUTION Never use the coarse adjustment end of the micrometer when measuring for caliper. The coarse adjustment will compress the paper fibers, resulting in an inaccurate reading. For example, if the fibers are compressed, 6 mm (0.24 inch) paper could measure as little as 3 mm (0.12 inch). Always use the fine adjustment to measure caliper. Using the fine adjustment, slide the micrometer along the edge of the paper and measure at one end. To double-check the accuracy of the reading, always measure again at the opposite end of the paper. Paper finish field test Paper finish, or smoothness, can be accurately measured with a Sheffield meter. If this tool is not available, a new U.S. dollar bill can be used as a benchmark for comparing paper texture. A dollar bill has a finish of 350 Sheffields. If paper feels rougher than a dollar bill, it is recommended that users do not continually use this paper in the printer. Moisture content field test Specification: Use paper with 4 percent to 6 percent moisture content. A package or a sheet of paper can be measured with a moisture meter. In general, only evaluate customer storage environment when trying to determine if excess moisture or dryness is the cause of a problem with paper. Grain field test Grain direction is usually specified on the package label (written out long or short ). The paper dimensions listed on the label also indicate grain direction. For example, short-grain letter-size paper labels are marked 11 by 8.5, and long-grain paper labels are marked 8.5 by 11." If grain direction is not included on the package label, it can be determined by a simple wet test. Cut a small square from the corner of a sheet of paper, wet it, and observe the manner in which it curls. Long, short, and diagonal grain curl 1-17