TAPPI T 435 om-16测量通过热萃取（未过滤并用沸水萃取一小时）获得的纸水提取物的氢离子浓度，以pH值表示。它可以应用于书写、打印和施胶工业用纸，但不适用于无缓冲类型 比如电绝缘纸和电容器纸。通过该方法确定的值将反映热诱导水解引起的变化。填充纸和涂布纸中使用的添加剂可能会对萃取pH值产生影响。TAPPI T 509“纸的氢离子浓度（pH）”中描述了冷萃取方法 提取物（冷提取法）。“纸的表面pH测量在TAPPI T 529“纸的表面pH测量”中进行了说明。"

TAPPI T 435 om-16 measures the hydrogen ion concentration, expressed in terms of pH, of an aqueous extract of paper obtained by hot extraction (unfiltered and extracted by boiling water for one hour).It may be applied to writing, printing and sized industrial paper, but it is not intended for unbuffered types such as electrical insulating and condenser papers. Values determined by this method will reflect changes resulting from heat-induced hydrolysis. Additives, such as those used in filled and coated papers can have an effect on the extract pH.The cold extraction method is described in TAPPI T 509, "Hydrogen Ion Concentration (pH) of Paper Extracts (Cold Extraction Method)."Surface pH measurement of paper is described in TAPPI T 529, "Surface pH Measurement of Paper."