Campbell CR850, Operator'S Manual

Page: 285 / 566

Section 8. Operation
285
Figure 90: Settling time for pressure transducer
Table 58. First Six Values of Settling-Time Data
TIMESTAMP REC PT(1) PT(2) PT(3) PT(4) PT(5) PT(6)
Smp Smp Smp Smp Smp Smp
1/3/2000 23:34 0 0.03638599 0.03901386 0.04022673 0.04042887 0.04103531 0.04123745
1/3/2000 23:34 1 0.03658813 0.03921601 0.04002459 0.04042887 0.04103531 0.0414396
1/3/2000 23:34 2 0.03638599 0.03941815 0.04002459 0.04063102 0.04042887 0.04123745
1/3/2000 23:34 3 0.03658813 0.03941815 0.03982244 0.04042887 0.04103531 0.04103531
1/3/2000 23:34 4 0.03679027 0.03921601 0.04022673 0.04063102 0.04063102 0.04083316
8.1.2.9 Self-Calibration
Read More! Related topics can be found in Offset Voltage Compensation
(p. 278).
The CR800 self-calibrates to compensate for changes induced by fluctuating
operating temperatures and aging. Without self-calibration, measurement
accuracy over the operational temperature range is worse by about a factor of 10.
That is, over the extended temperature range of -40°C to 85
°
C, the accuracy
specification of
±
0.12% of reading can degrade to
±
1% of reading with self-
calibration disabled. If the temperature of the CR800 remains the same, there is
little calibration drift with self-calibration disabled.
Note Self-calibration requires the CR800 to have an internal voltage standard.
The internal voltage standard should periodically be calibrated by Campbell
Scientific. When high-accuracy voltage measurements are required, a two-year
calibration cycle is recommended.