Air Detector - Fresenius Medical Care 4008 E Technical Manual

3.4

Air detector

Measuring equipment:
Place of measurement:
Check/adjustment:
– Adjust the ultrasonic detector
Install the measuring set-up before checking/adjusting the air detector. Do not yet place the
line in the occlusion clamp.
Jumper J1 / P.C.B. LP 450 set to calibration.
Fill the bubble catcher. The fluid level must be set to approx. 10 mm above the top edge of the
sensor holder.
Turn potentiometer 1 and potentiometer 2 on P.C.B. LP 450 clockwise, until the LED DI5 and
LED DI10 on P.C.B. LP 450 are dark.
Slowly (attention: time constant) turn potentiometer 1 on P.C.B. LP 450 counterclockwise,
until the LED DI5 on P.C.B. LP 450 lights.
Slowly (attention: time constant) turn the potentiometer 2 on P.C.B. LP 450 counterclockwise,
until the LED DI10 on P.C.B. LP 450 lights.
After completion of the calibration procedure, set the jumper J1 / P.C.B. LP 450 back to the
operation position.
– Check
Lower the level in the bubble catcher: an alarm must be emitted.
Raise the level in the bubble catcher: it must be possible to clear the alarm; both LEDs must be
off!
– Check the venous line clamp (
Place the line in the venous line clamp.
Open the clamp and, using the syringe, generate a pressure of approx. 2 bar.
Close the clamp.
The pressure must not drop by more than 0.1 bar within 3 minutes.
– Adjust the optical detector
Use the gray filter, double-laid, part no. 640 560 1.
Diagnostics menu; reading of digital inputs by CPU 1; item I: CPU1_OD_IN.
Install the gray filter, double-laid; close the hinged cover.
Slowly turn potentiometer 5 on P.C.B. LP 450 clockwise, until the UF display indicates 1111.
Slowly turn potentiometer 5 counterclockwise, until the display jumps to 0000. Continue to turn
the potentiometer counterclockwise for half a turn.
Avoid incident light from external sources.
Caution
For adjusting the air detector, the system must be in "Calibration" mode. The
ambient temperature should range between 15 and 35 °C.
Measurement setup according to diagram
UMED, HMED or pressure gauge, bubble catcher, syringe filled with
degassed water or saline solution

Air detector

Fresenius Medical Care 4008 4/08.03 (TM)
Fig. on p. 3-28)
3-29