为了初步探明负压场中木材平衡含水率如何受相对湿度、温度和绝对压力的影响，以俄罗斯产落叶松(Larix gmelinii Rupr.)小试件为试验对象，采用称重法测量真空罐内相对湿度40%~90%、温度45~70℃、绝对压力30~70kPa范围内木材的平衡含水率。在此基础上分析相对湿度、温度和绝对压力对木材平衡含水率的影响。结果表明：相对湿度从40%升高到90%，平衡含水率从6.13%增大到13.18%(50 kPa, 60℃)；温度从45℃升高到70℃，平衡含水率从16.60%降低到8.40%(70%, 50 kPa)；绝对压力从30 kPa提高到70 kPa，平衡含水率从6.66%减小到6.02%(50%, 70℃)。因此，负压场中木材平衡含水率随相对湿度升高而增大，随温度、绝对压力的升高而减小。

In order to analyze the influence of relative humidity, temperature and ambient absolute pressure on the wood EMC (equilibrium moisture content), the author chose small samples of Russian larch (Larix gmelinii Rupr.) as experimental material and measured their EMCs with the weigh method under the condition of relative humidity ranging from 40% to 90%, temperature ranging from 45℃ to 70℃ and ambient absolute pressure ranging from 30kPa to 70kPa in the vacuum tank. Then the influence of the relative humidity, temperature and absolute pressure on the equilibrium moisture content was investigated, respectively. Results indicated that: EMC of Russian larch increased from 6.13% to 13.18% as the relative humidity increased from 40% to 90% (70%, 50 kPa); EMC decreased from 16.60% to 8.40% as temperature increased from 45℃ to 70℃ (70%, 50 kPa); EMC decreased from 6.66% to 6.02% as ambient absolute pressure increased from 30 kPa to 70 kPa (50%, 70℃). Therefore, EMC of Russian larch under vacuum was affected as follows: it increased with the increasing relative humidity, decreased with the increasing temperature and ambient absolute pressure.