beautypg.com

9 self-calibration, Figure 90: settling time for pressure transducer, Table 58. first six values of settling-time data – Campbell Scientific CR1000 Measurement and Control System User Manual

Page 289

background image

Section 8. Operation

289

 

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. 282).

The CR1000 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 CR1000 remains the same, there is
little calibration drift with self-calibration disabled.

Note Self-calibration requires the CR1000 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.