User manual

8 1260 Nanoflow Pump User Manual

1 Introduction to the 1260 Infinity Nanoflow Pump

Introduction to the Pump

The low flow pumps consist of two identical pumping units in a single housing.

They generate gradients by high-pressure mixing. A solvent selection valve

provides flexibility in the choice of solvents.

Mobile phase composition is produced by mixing the outputs of pumphead A

and B. The solvent selection valve allows the pumphead A output to originate

from either channel A1 or channel A2. The pumphead B output may originate

from either channel B1 or channel B2.

In order to deliver fast gradients over the whole composition range, the two

pumpheads deliver a primary flow of 200 – 1100 µL/min from which a mass

flow sensor controlled electromagnetic proportioning valve (EMPV) splits the

set column flow. Excessive solvent is diverted to waste. This electronic flow

control automatically compensates for changes in solvent properties and

backpressure throughout a run.

Solvent degassing is not done directly in the pump. A 4-channel, low volume

micro vacuum degasser, available as a separate module, provides degassed

solvents to the pump channel inputs. Solvent degassing is required for best

flow stability and detector stability, especially at the low flow rates required to

run capillary/nano LC applications.