Process Sensors MCT 300, Инструкция по установке и эксплуатации

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8.3 On-line Offset Trim Adjustment
Install the sensor on the moving process line. Grab 2-3 samples of the product and note the sensor’s
reading for each sample. For a more accurate calculation of the sensor’s readings during the collection
of the each sample, the sensor’s “grab sample average feature” may be used. Refer to section 7.3 for
more details on the use of this feature.
Calculate the average of the three sensor readings and of the three true moisture values.
Adjust the zero setting as follows:
New Zero = Old Zero - (Sensor Average - True Moisture Average)
8.4 Linear Regression Statistics
The sensor’s computer calculates several statistics during its calibration routine; these statistics give a
measure of the accuracy and quality of the calibration.
Correlation Coefficient:
This is an expression of how well the sensor readings
match the True values.
1.0 is perfect
Greater than 0.9 is acceptable
Less than 0.9 is not acceptable
Standard Error
: This is a gauge of the accuracy of the calibration. A perfect
value is 0.0. Acceptable values are in the 0.0 to 0.5 range
depending on the moisture ranges being measured.
8.5 Online Multi-Sample Calibration
If, due to the nature of the product, it is not possible to make sample with varying moisture levels, then
an online calibration may be necessary. Careful planning and sample taking is needed to ensure an
accurate calibration.
Samples should be taken at, at least 3 different moisture levels. Two samples should be taken at each
moisture level. The moisture levels should be as wide as possible, but at least +/- 5% of the target
moisture. In a similar way to the static calibration tabulate the paired data of sensor readings and
laboratory determined true moisture values. Use the Operator Interface or PC software to calculate the
correct Zero and Span settings.
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