颗粒计数器

我用纳米粒度仪测出粒子是一微米左右 而且PDI很小 只有0。0几 而用TEM照出可能只有100nm左右 请问是怎么回事？

纳米粒度仪=激光粒度仪？激光粒度仪测得是二次粒子，即团聚后的粒子尺寸。

团聚，这个肯定的无法避免

The discrepancy between the DLS and electron
microscopy diameters is partly due to polydispersity effects (since
DLS is more biased toward larger particles than TEM and SEM)and also reflects the swollen dimensions of these microgels in
aqueous solution (compared to the high-vacuum conditions
required for electron microscopy).

同意，粒度仪测定通常为溶解液，材料在溶剂中出现溶胀；TEM为干燥样，测量的更准确些。

纳米粒度仪测的是平均粒度,TEM在制样时先用超声波将颗粒分散,再静置一会用滴管吸取悬浊液,所以大颗粒都沉底啦.

两者的侧重点不一样，TEM的信息要更全，更微观一些。

游标卡尺， 膜厚度用椭偏仪， 很薄的化用AFM