Calibrating Low Pressure Cell

[Toshio]

I've got an HP 1090 giving a flow reduction (FlRe) error. I think its the low pressure cell. How do I go about calibrating it using the two screws on the side? What do those do and how sensitive are they?

I know they aren't to be tampered with. But its understood that any damage I cause is my fault and not whoever is giving me advice.

[HPLCCONSULT]

I think you are referring to the sensor connected to the LPC "Low Pressure Compliance" device ?? There is also a high pressure transducer located in the behind the pulse dampener too. Both use strain gauges which output a voltage and wear over time (esp in systems that are now twenty years old). Per Factory spec, they should not be adjusted if worn, but rather replaced instead. If you want to adjust them you can monitor the output on a separate meter. *They are very sensitive.

BTW: A flow reduction error can be caused by many things. A bad sensor reading is just one of them. Insure that your low pressure pumps and rotary valves are working perfectly first.