pH electrode (optional)
The pH electrode, AE-121, is an optional accessory (see
Section 14.4 Ordering information,
). The electrode can be mounted in a holder on top of pressure cell PT-112.
When a flow kit is delivered, a dummy is located in the pH electrode holder. Unlike the
rest of the flow kit, the pH electrode has not been autoclaved or subjected to gamma
radiation at delivery and must therefore be cleaned by the user.
The pH electrode should be calibrated at least once a day (see
Flow meter cell
The flow meter cell, FE-141, is placed after the pressure cell PT-112/pH electrode AE-121
in the flow path. The flow meter measures the liquid velocity using ultrasound. Transduc-
ers are connected to both sides of a straight channel through the cell. The difference
between upstream and downstream ultrasound velocity is measured and the result is
used to compute the flow. In order to ensure proper transmission of the sound energy,
the contact surfaces should be coated with a thin layer of Vaseline™ delivered with the
flow kit or similar lubricant before the transducers are connected.
Air sensor
The air sensors, AE-151 and AE-152, are high precision monitors designed for continuous
monitoring of air bubbles in the flow path. When air is detected, the system is either
paused, or performs an action that is set in the method.
Temperature sensor
The temperature sensor, TE-161, is located on the front of the system cabinet, beneath
the flow meter cell. The sensor measures the infrared radiation emitted from a dedicated
measurement window in the body of the flow meter cell. A lens in front of the sensor
focuses the infrared radiation.
A system that is not properly temperature equilibrated may produce incorrect
temperature readings. Therefore, if the system or flow kit is moved between
rooms with different temperatures, time must be allowed for the equipment
to adjust to the new ambient temperature. In particular, the body of the flow
meter cell may need several hours to adjust to room temperature.
Note:
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ÄKTA ready Operating Instructions 28960345 AD
3 System description
3.4 Equipment
