Waters ACQUITY UPLC Operator's, Overview And Maintenance Manual page 6

A receptacle on the column heater's right-hand side receives the column's
eCord™ chip. The eCord column chip stores column manufacturing and usage
data, which you can access from the ACQUITY UPLC Console.
The column heater does not have its own power supply; it draws power from
the sample manager. Thus the column heater is automatically powered-on
when you power on the sample manager.
The ACQUITY column heater (CH-A) cannot be used in
Restriction:
conjunction with the optional 30-cm column heater (CH-30A).
Active preheater
The standard, active preheater uses an electric heating element to directly
heat the column inlet tubing. The rapid heating, low volume design reduces
gradient delay and extra-column bandspreading. It ensures that high flow
rate separations occur at the column temperature, not at the temperature of
the incoming solvent. By controlling the temperature of the mobile phase at
the point of use—the column inlet—temperature differences introduced by
variations in the system configuration are eliminated.
Active preheater:
If you use the active preheater when running an HPLC or UPLC method
originally developed for use with a column stabilizer, adjusting the column
temperature can be necessary.
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