Campbell CR800 Series, Operator'S Manual

Page: 216 / 598

Section 7. Installation
216
software documentation available at www.campbellsci.com . Be aware of the
following precautions:
•
The CR800 does not check for out-of-bounds values in mode variables.
• Valid mode variable entries are
1
or
4
.
Before, during, and after calibration, one of the following codes will be stored in
the CalMode variable:
FieldCal() Codes
Value Returned State
-1 Error in the calibration setup
-2 Multiplier set to 0 or NAN ; measurement = NAN
-3 Reps is set to a value other than 1 or the size of
MeasureVar
0 No calibration
1 Ready to calculate ( KnownVar holds the first of a
two point calibration)
2 Working
3 First point done (only applicable for two point
calibrations)
4 Ready to calculate ( KnownVar holds the second of a
two-point calibration)
5 Working (only applicable for two point calibrations)
6 Calibration complete
7.7.11.4.1 One-Point Calibrations (Zero or Offset)
Zero operation applies an offset of equal magnitude but opposite sign. For
example, when performing a zeroing operation on a measurement of 15.3, the
value –15.3 will be added to subsequent measurements.
Offset operation applies an offset of equal magnitude and same sign. For
example, when performing an offset operation on a measurement of 15.3, the
value 15.3 will be added to subsequent measurements.
See FieldCal() Zero or Tare (Opt 0) Example
(p. 218)
and FieldCal() Offset (Opt 1)
Example
(p. 220)
for demonstration programs:
1. Use a separate FieldCal() instruction and variables for each sensor to be
calibrated. In the CRBasic program , put the
FieldCal()
instruction
immediately below the associated measurement instruction.
2. Set mode variable = 0 or 6 before start ing.
3. Place the sensor into zeroing or offset condition.