HP 2100 Service Manual - Page 50

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 mil paper could measure as little as 3 mils. 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, use a new U.S. dollar bill as a benchmark for comparing paper texture. A dollar bill has a finish of 350 Sheffields, which is 100 over specifications. if paper feels as rough as 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 4-6% moisture content. A ream or sheet of paper may be measured with a moisture meter. In general, only evaluate the customer's storage environment when trying to determine if excess moisture or dryness is the cause of a problem with paper. Grain Field Test The grain direction is usually specified on the ream label (written out "long" or "short"). The paper dimensions listed on the label also indicate grain direction. For example, short grain letter size paper will read "11 x 8.5" and long grain will read "8.5 x 11." If the grain direction is not included on the ream 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. 40 Chapter 2 Operating Requirements C4170-90959