Caliper field test The specified caliper differs with the type of media used. See “Operating environment” on page 26 Caliper can be measured in the field 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 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 percent to 6 percent moisture content. A ream or sheet of paper can 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 by 8.5" and long-grain paper will read “8.5 by 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.
Envelopes should have a diagonal grain, which gives them the best stability. To determine this, cut a square section from one corner of an envelope. Wet this section and observe the manner in which it curls. Two opposite corners should curl toward each other. Figure 14. Long, short, and diagonal grain curl C7058-90936 Media specifications 39