新西兰标准与我国国标在原木检尺方面的差异

Core Viewpoint - Understanding the technical details of wood measurement standards can help reduce trade disputes and cost fluctuations in the wood trade between New Zealand and China [1] Group 1: Differences Between JAS and National Standards - New Zealand's JAS standard and China's national standard differ in measurement methods and specifications for wood, leading to discrepancies in wood volume calculations and potential cost impacts [2][27] - The "growth measurement" phenomenon occurs when converting cubic meters between JAS and national standards, affecting the actual import costs of certain wood species [2][27] Group 2: JAS Standard Measurement Details - The JAS standard focuses on assessing the volume of logs, requiring measurements of the diameter at the small end and the length, using specific formulas developed by Japan's Ministry of Agriculture, Forestry and Fisheries [3][6] - Length is measured as the shortest distance between the two ends of the log, with a tolerance for slight overcuts to ensure compliance with agreed lengths [3] - The measurement of diameter involves specific rounding rules based on the size of the log, with different methods for diameters below and above 14 cm [4][5] Group 3: National Standard Measurement Details - China's national standard measures log length and diameter with specific rounding rules, differing from the JAS standard in both methodology and measurement units [13][14] - The national standard specifies that logs shorter than 5.8 meters are rounded to the nearest 0.1 meter, while longer logs have different rounding rules [14] - Diameter measurements are taken to the nearest millimeter, with specific rules for rounding based on the size of the log [16][18] Group 4: Market Discrepancies in Measurement - Despite using the national standard as a basis, there are discrepancies in measurement practices across different domestic markets in China, leading to variations in measurement results [27][29] - For instance, the Shandong market may experience "virtual measurement" where results are rounded up, while the South China market may adopt stricter measurement practices, affecting pricing [29]