Siemens RAPIDLAB 248 Operator's Manual page 85

Troubleshooting the System
Measurement Block Routine
Nominal mV
Total pull in range
Action limits
Nominal pA
Total pull in range
Action limits
Action: pH - may be caused by the reference sensor, see Pages 4-1 and 4-2. If
* at 760 mmHg atmospheric pressure, using standard gases (Cal: 5% CO
12% O
4. Stability – for 7.3 Buffer and Cal Gas a typical sensor will show the
Noise - after 15 seconds
the display will not
change by more than:
Drift - after 15 seconds
the display will not
change unidirectionally
by more than:
during the remainder of the measurement.
Instability on the pH channel may be caused by the reference sensor.
De-bubble the reference sensor and repeat the test.
5. Press * to cancel the test.
Run Test Sample
1. You can use the run test sample option to:
NOTE:
routine.
Cal Gas pCO
–170.0
-300.0 to +100.0
< -270.0 or >+80.0
Cal Gas pO
+764.0
171 to 1961 above
slope gas pA value
<300 or >1600 above
slope gas pA value
problem persists condition or refill the pH sensor. If the problem is still
apparent, replace the pH sensor.
pCO /pO - deproteinize/replace sensor
2 2
and Slope: 10% CO
2
following performance:
a. Measure a sample with a known mV value (for example, run 7.3
or 6.8 buffer as a sample).
b. Run QC samples to promote stability after installing a new
sensor.
You cannot use capillary samples with the Run Test Sample
(mV)
2
(pA)
2
and 0% O )
2 2
pH pCO
0.2 mV/10 secs 1.0 mV/10 secs 2 pA/10 secs
1.0 mV 5.0 mV
Page 4-11
Slope Gas pCO (mV)
2
–151.0
12.8 to 21.1 above
cal gas mV value
<13.5 or >20.2 above
cal gas mV value
Slope Gas pO (pA)
2
+80.0
–100.0 to +250.0
<–50 or >200
pO
2 2
15 pA
,
2