Conductivity; Changing Conductivity Limits - Fresenius Medical Care 2008T Operator's Manual

Chapter 3—Setting Treatment Parameters

Conductivity

The Theoretical Conductivity (TCD) represents the expected conductivity for the selected
concentrate at the set Na+ and bicarbonate levels. It is displayed above the electrolyte
constituents on the left side of the "Dialysate" screen (see Figure 29 on page 64). The actual
conductivity of the Final Dialysate is displayed above the conductivity bar graph on the right
side of the "Dialysate screen." It is represented by a horizontal bar in the conductivity graph.
The bar appears green when the conductivity is within alarm limits, and turns red when the
actual conductivity is outside the alarm window. With both concentrate supplies connected
to the machine, a stable, accurate conductivity reading should be attained about five minutes
after the concentrate is confirmed in the "Dialysate" screen.
Conductivity Limits
As the operator changes the sodium or bicarbonate settings, the TCD (Theoretical
Conductivity) will change. The alarm limits are set around the TCD. The alarm window is
the area between the upper and lower alarm limits. The upper and lower alarm limits are
shown by yellow horizontal lines in the conductivity bar graph. They are set 0.5 mS/cm
above and below the TCD by default. The conductivity alarm sounds when the actual
conductivity of the dialysate climbs or falls outside of this window. The alarm window can be
shifted up or down to within 0.5 mS/cm of the default setting using the Alarm Position
button (and the Keyboard), and widened or narrowed using the Alarm Width button (and the
Keyboard). The width of the alarm window can be set from a minimum of 0.6 mS/cm to a
maximum of 1.0 mS/cm, within the range of 12.5–16.0 mS/cm.
The following examples illustrate how to set the conductivity alarm window:
Upper and lower alarm limits
Figure 33 – Changing Conductivity Limits
72
2) To shift the alarm window upward,
press the  (up) arrow key. To shift
the window downward, press the 
(down) arrow key.
2008T Machine Operator's Manual P/N 490122 Rev N
1) To access the
position of the
conductivity alarm
window, select Alarm
Position.
3) Press the
CONFIRM key to
save the change.