Table 55. ac noise rejection on small signals, Table 56. ac noise rejection on large signals – Campbell Scientific CR800 and CR850 Measurement and Control Systems User Manual
Page 287
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Section 8. Operation
287
measurements (B) to be determined during CR800 self-calibration (maximum of
54 values). These values can be viewed in the Status table, with entries identified
as listed in table Status Table Calibration Entries
(p. 287).
Automatic self-calibration can be overridden with the Calibrate() instruction,
which forces a calibration for each execution, and does not employ any low-pass
filtering on the newly determined G and B values. There are two parameters
associated with the Calibrate() instruction:
CalRange
and
Dest
.
CalRange
determines whether to calibrate only the necessary input ranges for a given
CRBasic program (
CalRange
= 0) or to calibrate all input ranges (
CalRange
≠ 0).
The
Dest
parameter should be of sufficient dimension for all the returned G and B
values, which is a minimum of two for the automatic self-calibration of VoltSE()
including B (offset) for the ±2500 mV input range with first 250 µs integration,
and a maximum of 54 for all possible integration durations and input-voltage
ranges chosen.
An example use of the Calibrate() instruction programmed to calibrate all input
ranges is given as:
'Calibrate(Dest,Range)
Calibrate
(cal(1),true)
where
Dest
is an array of 54 variables, and
Range
≠ 0 to calibrate all input ranges.
Results of this command are listed in the table Calibrate() Instruction Results
(p.
Table 59. Status Table Calibration Entries
Descriptions of Status Table Elements
Status Table
Element
Differential (Diff)
Single-Ended (SE)
Offset or Gain
±mV Input
Range
Integration
CalGain(1)
Gain 5000 250
ms
CalGain(2)
Gain 2500 250
ms
CalGain(3)
Gain
250 250
ms
CalGain(4)
Gain
25
250
ms
CalGain(5)
Gain
7.5
250
ms
CalGain(6)
Gain
2.5
250
ms
CalGain(7)
Gain 5000
60-Hz
Rejection
CalGain(8)
Gain 2500
60-Hz
Rejection
CalGain(9)
Gain
250
60-Hz
Rejection
CalGain(10)
Gain
25 60-Hz
Rejection
CalGain(11)
Gain
7.5 60-Hz
Rejection
CalGain(12)
Gain
2.5 60-Hz
Rejection
CalGain(13)
Gain
5000
50-Hz
Rejection
CalGain(14)
Gain
2500
50-Hz
Rejection
CalGain(15)
Gain
250
50-Hz
Rejection
CalGain(16)
Gain
25 50-Hz
Rejection
CalGain(17)
Gain
7.5 50-Hz
Rejection