Gilson 402 - Manual (Page 23)

2-5
Description
2
Hydraulic Components
Valve
The two-position valve, which is fitted to the left-
hand side of the 402, has three ports. It switches
the syringe port to either the reservoir or to the
probe side (see opposite figure).
The valve, which has a 0.5 sec rotation period, is
driven by a stepper motor. It is designed to with-
stand a million rotations, when used with water.
The liquid contact surfaces of the valve, which is
autoclavable, are in PEEK and ceramic (121°C,
0.1 MPa, 20 min).
Tee Junction
The Tee-junction, which is fitted to the right-hand
side of the dual-syringe model, has three ports: the
inlet from the valve, the outlet to the probe, and the
syringe port (see opposite figure).
The Tee-junction, which has no internal moving
parts, includes 2 channels, each 1.5 mm in diam-
eter oriented at 120°. The liquid contact surfaces of
the Tee-junction, which is autoclavable, are in PEEK.
Syringes
The choice of syringe allows the 402 Dilutor-Dispenser
to handle volumes from 1 µL to 25 mL with low
values of systematic and random error. The 402
Dilutor-Dispenser is able to transfer liquid as
follows:
- from 1 µL to 10 mL from the probe (transfer
tubing volume of up to 10 mL),
- up to 25 mL from the reservoir, in one stroke,
- up to 99 mL from the reservoir, in several strokes.
When using the Dual-syringe model, a theoretical
dilution ratio of 1/25000 is achieved in one stroke
of both sample and diluent syringes. However, you
are advised not exceed a ratio of 1/500 for any
given dilution, in order to stay within the RSD
range (after efficient mixing).
Hydraulic Components
From reservoir
Probe (or Tee
junction)
To waste
Syringe
From Valve To Probe
Syringe