7.1 Measuring interface
￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
36
￭￭￭￭￭￭￭￭
867 pH Module
7 Technical specifications
7.1
Measuring interface
The 867 pH Module has one galvanically isolated measuring interface.
The measuring cycle is 100 ms for all measuring modes.
7.1.1
Potentiometry
One high-ohm measuring input (
Ind.
) for pH, metal or ion-selective elec-
trodes and one measuring input (
Ref.
) for separate reference electrodes.
Input resistance
> 1 · 10
12
Ω
Offset current
< 1 · 10
–12
A (under reference conditions)
Measuring mode
pH
Measuring
range
–13 - +20 pH
Resolution
0.001 pH
Measuring
accuracy
±0.003 pH
(±1 digit, without sensor error, under reference conditions)
Measuring mode
U
Measuring
range
–1200 - +1200 mV
Resolution
0.1 mV
Measuring
accuracy
±0.2 mV
(±1 digit, without sensor error, under reference conditions)
Measuring mode
Conc
Measuring
range
10
–21
…10
20
Resolution
Measuring
accuracy
(±1 digit, without sensor error, under reference conditions)
