Uf Calibration; General - Gambro AK 95 S Service Manual

UF Calibration

General

This section describes the calibration routine of
the UF-measuring unit.
The UF-measuring unit consists of two flow
measurement channels called channel 1 (CH 1)
and (CH 2). CH 1 is the channel used to measure
the main flow to the dialyser and CH 2 is used to
measure the flow from the dialyzer, i.e. the sum
of the main flow and the UF flow. The UF flow is
the difference between CH1 and CH2 flows. UF
flow is also called differential flow.
Perform both a disinfection and a cleaning
decalcification to remove both organic and
calcium precipitates, according to the AK 95 S
Operator's Manual.
The calibration routine can be run in 3 different
modes. The modes are Complete, Intern and
Verify.
- Select Complete for an automatic UF
calibration.
- Select Intern for an internal calibration
(taration but updating the EEPROM instead of
RAM). This is done without the external UF
calibration equipment connected to the
AK 95 S.
It is not possible to select Intern if not a
complete UF calibration has been done on the
UF cell before.
- Select Verify for a verification of the result
from the latest calibration.
AK 95 / AK 95 S Service Manual
HCEN 9138 Rev. 10.2005
High Level
V.ref.
Low Level
UFVA
Fig. The AK 95 S UF calibration system.
The Complete calibration routine is done with
the mainflow 500 ml/min. It requires that the
external UF calibration equipment is connected
to the AK 95 S, see fig.below. The equipment
contains a reference volume, a flow directing
valve (UFVA) and a UF- calibration box. The
UF calibration box controls the directing valve
by measuring low level and high level of the
reference volume and depending on the selected
UF box mode the valve will become closed or
opened when low or high level is detected.
UF calibration equipment, ordering no.
K2 1908 002
Note! Tubes used to connect the reference
volume to the monitor should not be longer than
standard tubes used for connection of dialysers.
The connection tubes should be routed so that
"air traps" are avoided.
Note!
Make sure the +500ml/min restrictor is mounted
before calibration.
AK 95 S
AK 90
Flow in/out
Calibrations
UF
Cal.
Box
6:17