20
The pH mA output will produce a linear analog output if the
user selects ‘LINEAR’ in pH mA SETTING page (see
figure 2
). The
temperature mA output is always linear. The pH analog output is
calculated using
pH_4 mA setting, pH_20 mA setting
and the
current pH display.
An independent mA OUT page for
temperature is available
The pH LINEAR & Temperature analog output is based on the
following equations respectively:
mA
(pH)
= 4mA+(16mA)*(D
(pH)
- pH(4) ) / (pH(20) - pH(4))
mA
(Temp)
=4mA+(16mA)*(D
(Temp)
- TEMP(4) ) / (TEMP(20) - TEMP(4))
Where:
mA
(pH)
& mA
(Temp)
= analog output
D
(pH)
& D(
Temp
)
= current pH & Temperature display
pH(4) & TEMP(4) = pH & Temperature user setting for 4 mA
pH(20)& TEMP(20)= pH & Temperature user setting for 20 mA.
Note :
1. The range for 4mA and 20mA settings is 0.00 to 14.99 in pH or 0
to 120
℃
in temperature.
2. The absolute difference of the 4mA and 20mA settings must be
greater or equal to 0.10pH in pH or 1.0
℃
, if less than this value the
analog output will be disabled.
