ABL77 Service Manual
Chapter 4: Test and Calibration Procedures
Electronic Zero Offset,
Continued
Verify zero
offset
(continued)
Step Action
6.
Press
Set 0
to zero all channels
7.
•
The O2(nA) channel should fall within -0.010 to +0.010 nAmps.
•
The pH, CO
2
, and ISE channels should fall within –0.1 to +0.1 mV
•
The Hct channel should fall within –20 to +20 AD counts
•
The Th channel should read 36.5 to 37.5
8.
Remove the zeroing cassette.
•
The pH, CO
2
, and ISE channel values will begin to “float”. This is
normal and expected.
•
The Hct channel should remain at zero (
±
20)
•
The Th channel should read 100
•
The O
2
channel should remain at zero (
±
0.010)
9.
•
If the Hct channel does not remain at zero, replace the analog board
•
If the Th channel does not read 100, replace the analog board
•
If the O
2
channel does not remain at zero, first replace the valve
board. If this does not solve the problem, replace the analog board.
Rev. F
4-35
