Hi. I have problem with on-line counting
because air in oil causing wrong results.
How to solve it?

Another problem is when i take bottle sambling
laboratory gets higher contamination levels
with counter and lower with microscope in same
samble. Maybe grease or corrosion cover causing
this? Water is not problem ( 40 ppm)

If the air bubbles interfere with in-line counter you may try some less turbulent spot to connect in.
As for the different readings from lab counter and microscope, it is not surprising, because there are totally different techniques. While counter reads from continues flow, microscopic counting are limited to an area. Basically, you will have to decide on which technique you are going to base you testing and trending. Running both will get you nowhere. And if you choose a counter technique, request ISO 4406/99 capable one. It is calibration based reading, and results from different labs of the same sample should be comparable.

I am looking for the operation manual for
an old particle counter equipment,

Hiac Royco liquid particle counter
model VCHV-PE

Can anyone help?