Vaisala PR-23 Series User Manual

4 Field calibration: Adjustment of the calculated concentration value CALC may be
r
equired to compensate for some process conditions or to fit the measurement to the
laboratory results. The field calibration procedure, see Field calibration (page 75),
determines the appropriate adjustment to CALC. The adjusted concentration is called
CONC. If there is no adjustment, CALC and CONC are equal. Therefore the chemical
curve is kept intact as a firm base for the calculation, the adjustment is merely
additional terms.
5 Damping: see Configuring output signal damping (page 59).
6 Output signal: The range of the 4 … 20 mA signal is defined by its two endpoints on the
CONC scale, see Configuring mA outputs (page 70).
7.4.1 Chemical curve
The chemical curve is the theoretical concentration curve based on n
D
and TEMP
. It is
defined by a set of 16 parameters.
Table 7 Chemical curve parameters
C
00
C
0
1
C
02
C
03
C
10
C
11
C
12
C
13
C
20
C
21
C
22
C
23
C
30
C
31
C
3
2
C
33
A chemical curve is specific t
o the given process medium, for example, sucrose or sodium
hydroxide. The set of parameters is given by Vaisala and should not be altered, except in
case of changing to another process medium. The parameters can be changed by selecting
5 CALIBRATION from the Main menu, then, in the Calibration menu, 1 CHEMICAL & FIELD
PARAMETERS, and finally 1 CHEMICAL CURVE PARAMETERS.
7.4.2 Selecting display units and display decimals
The display units and display decimals are set separately for each sensor, so fir
st go to the
Calibration menu of the correct sensor. Then select 2 OUTPUTS in the Calibration menu and
in the Outputs menu choose either 1 DISPLAY UNITS or 2 DISPLAY DECIMALS. For the
display units, select either 1 CONCENTRATION or 2 TEMPERATURE and then the unit. For
display decimals, enter the number of decimals you want to see on display by entering a
number in the range 0 … 5 (0 meaning no decimals are shown).
Change of concentration unit does not change the numerical value of the concentration.
Change of temperature unit recalculates the numerical temperature value according to
selected scale (°C or °F).
PR-23 Series User Guide
IM-EN-PR23-E
74

Vaisala PR-23 Series Specifications

General

Brand	Vaisala
Model	PR-23 Series
Category	Measuring Instruments
Language	English