Hitachi L-2100 Instruction Manual page 88

Check Location
3. The flow path
filter of the drain
valve is easily
contaminated.
4. The pump is the
main component of a
high speed liquid
chromatograph.
Procedure
Wash the filters with an
ultrasonic cleaner every
4 months.
1) The pump seal is a
consumable part!
Be sure to replace
the seals
periodically.
2) The high pressure
pump must be kept
clean!
Clean the pump every
month.
For cleaning, just
pass isopropanol
through the pump for
30 minutes.
3) The high pressure
pump does not function
properly when
there are bubbles.
Before exchanging the
solvent bottle or
adding solvent into
the bottle, be sure
to turn off the pump.
5 - 7
Remarks
The filters prevent
wornout fragments of the
pump seal from flowing
into the column. If the
filter is contaminated,
the pressure increases
abnormally.
• Deterioration of the
seal causes leaks.
Leaks lead to poor
baseline stability and
data reproducibility.
The net result of leaks
is degradation of
reliability in
measurement.
• Contamination of the
check valve, which is
the critical part in a
high pressure pump,
causes pressure
fluctuations, a failure
in the pressure rise or
easy adhesion of air
bubbles.
• Air bubbles in the pump
cause pressure to
fluctuate or fail to
rise.