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CR1000 Manual - Campbell Scientific

CR1000 Manual - Campbell Scientific

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Section 8. Operation<br />

Figure 90: Settling time for pressure transducer<br />

Table 58. First Six Values of Settling-Time Data<br />

TIMESTAMP REC PT(1) PT(2) PT(3) PT(4) PT(5) PT(6)<br />

Smp Smp Smp Smp Smp Smp<br />

1/3/2000 23:34 0 0.03638599 0.03901386 0.04022673 0.04042887 0.04103531 0.04123745<br />

1/3/2000 23:34 1 0.03658813 0.03921601 0.04002459 0.04042887 0.04103531 0.0414396<br />

1/3/2000 23:34 2 0.03638599 0.03941815 0.04002459 0.04063102 0.04042887 0.04123745<br />

1/3/2000 23:34 3 0.03658813 0.03941815 0.03982244 0.04042887 0.04103531 0.04103531<br />

1/3/2000 23:34 4 0.03679027 0.03921601 0.04022673 0.04063102 0.04063102 0.04083316<br />

8.1.2.9 Self-Calibration<br />

Read More! Related topics can be found in Offset Voltage Compensation (p. 282).<br />

The <strong>CR1000</strong> self-calibrates to compensate for changes induced by fluctuating<br />

operating temperatures and aging. Without self-calibration, measurement<br />

accuracy over the operational temperature range is worse by about a factor of 10.<br />

That is, over the extended temperature range of -40°C to 85°C, the accuracy<br />

specification of ±0.12% of reading can degrade to ±1% of reading with selfcalibration<br />

disabled. If the temperature of the <strong>CR1000</strong> remains the same, there is<br />

little calibration drift with self-calibration disabled.<br />

Note Self-calibration requires the <strong>CR1000</strong> to have an internal voltage standard.<br />

The internal voltage standard should periodically be calibrated by <strong>Campbell</strong><br />

<strong>Scientific</strong>. When high-accuracy voltage measurements are required, a two-year<br />

calibration cycle is recommended.<br />

289

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