Metrohm 781 pH/Ion Meter - Manual (Page 145)

9 Annex
780/781 pH/Ion Meter, Manual
135
9 Annex
In this section you will find the most important technical data of the
pH/Ion Meter, a description of evaluation principles, dialog structures,
buffer tables, a description of the optional remote box, a list of standard
accessories and optional accessories as well as warranty and declara-
tions of conformity.
9.1 Technical data
Provided that nothing to the contrary is mentioned, the published val-
ues represent the typical data of the 780 pH Meter and the 781 pH/Ion
Meter.
9.1.1 Measuring modes
Measuring mode
Prim. measured
quantity
Sec. measured
quantity
pH pH T
Temperature T
Potential U
Concentration (781 only) Conc T
9.1.2 Measuring inputs
Potentiometric
for pH (780/781), potential (780/781), concentration (781)
- 1 high-impedance measuring input for pH, redox and ISE electrodes
- 1 reference input for separate reference electrode
Input resistance
Offset current
> 1 * 10 12 Ohm
< 1 * 10 –12 A
(under reference conditions)
Temperature
Also for automatic temperature compensation
- 1 measuring input for temperature sensors (Pt1000 or NTC)
NTC characteristics configurable
Default values R(25°C) = 30000 Ohm / B
25/50
= 4100
Measuring interval
Measuring cycle 100 ms for all measuring modes