Ahlborn ALMEMO 6290-7B, Руководство по эксплуатации, Страница: 27 / 53

Sensor Adjustment
To simplify the correction of sensors for the zero point and, possibly, also the
slope (gain), a key combination for an automatic adjustment is available in
function
MEASURE
(see 7.1.3). The corrected measured value is stored as zero
point correction and will be set to zero. However, the base value will be
maintained.
Function MEASURE: Adjustment with keys: ,
ENTER
For some sensors special functions are available in this context:
1. Dynamic pressure probes are very delicate and should be adjusted in an
unpressurized state before each use (i.e. disconnected hoses or Pitot tube
out of flow). The correction value must be entered before the conversion
'pressure-to-velocity' is performed. For the ranges L840 and L890 an
adjustment is possible even if the channel is locked. The zero point error is
temporarily written in the calibration offset until the switch-off is performed.
2. With the following sensors, a slope adjustment is performed in the same
way for the corresponding calibration value:
pH probe: pH4 or pH10
Conductivity: 2.77mS/cm (FY A641-LF) or 147µS/cm (FY A641-LF2)
O
2
saturation: 101% (FY A640-O2)
6.6 Scaling, Decimal Point Setting
For indicating the electrical signal of a sensor as a measured value of a
physical variable it is, in most cases, necessary to set a zero point shift and to
perform a multiplication with a certain factor. The functions BASE and
FACTOR and EXPONENT are available for this. A detailed description of the
scaling, including an example, can be found in the manual section 6.3.11.
Indicated value = (corrected measured value - BASE) x FACTOR.
Function BASE VALUE ´
BA
´
Selection with key
FUNCTION
... Input accord. to 5.4
1:- 7.0 0
BA
Function FACTOR ´
FA
´
Selection with key
FUNCTION...
Input accord. to 5.4
1:1.0 3 5 0
FA
Clear with keys: ,
ENTER
Clr
1: - - - -
FA
ALMEMO
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6290-7B 26
Sensor Programming