2021-07-27【求助】pH计校正时校正曲线斜率的标准是什么？

自己顶下。求高人指点。

关于三点校正的pH计没有用过，不是很清楚具体的操作查了一下网络关于Three-pointcalibration的操作好像有2种，有的是选择atpH4.0,7.0and10.0三个pH的缓冲溶液;然后automaticallyprovidesoffsetandtwoslopeadjustments还有就是Thethree-pointcalibrationdoesnotrequirethreebuffersolutions,butitrequirescalibrationat2differenttemperatures.FirsttheZEROandSLOPEaredeterminedbynormalbuffercalibrationatstandardreferencetemperature.ThenthebuffersolutionwithapHvaluedifferentfromtheITPvalueiswarmedupandtheintersectionwiththepreviouslycalibratedstandardtemperaturelineiscalculated.而关于斜率，有如下：MeterSlopeTheslopeisanimportantpartofthecalibrationprocess.Itwillverifytheaccuracyofthecalibrationperformed.IfMeterDisplaysSlopeUnitsthatdisplaycalibrationslopes,shouldhaveaslopeof–57.0to–62.0or57.0to62or95to105.Sloperangesdependontheindividualmeter.IfMeterDoesnotDisplaySlopeUnitsthatdonotdisplaycalibrationslopesshouldverifytheaccuracyofthecalibrationbyconductingthefollowingprocedure:Add5gramsofpowderedlimeto100to300mLofroomtemperature(25°Cor77°F)tapwater.Stirtomixsolution.TakeapHreADIng.ThepHshouldbebetween12.4and12.5.IfthepHisoutsideofthisrange,thentheslopeisinaccurateandacalibrationmustbeconductedagain.不清楚你们pH计到底什么操作进行三点校正？到底需要几个缓冲溶液？需要用到温度进行校正吗？（已考虑pH温度补偿）

谢谢longbow版主。仪器是梅特勒的SevenMulti，校正时用pH4.0,7.0and10.0三个pH的缓冲溶液进行。pH计自动进行温度补偿。其正常校正斜率为约59mV/pH。看来斜率范围应该象斑竹提到的那样，为57到62。再次感谢。

对截距也是有要求的，pH轴上一般不要超过7±0.5，能达到±0.1最好。

请问pH的截距要求在分析化学书上有没有介绍？