7 appendix, 1 technical data, 1 conductivity measurement – Metrohm 761 SD Compact IC User Manual
Page 115: 2 conductivity detector, Appendix, Technical data, Conductivity measurement, Conductivity detector, N 7 appendix
7.1 Technical data
761 SD Compact IC / Instructions for Use 8.
761.1043
107
7 Appendix
7.1 Technical
data
Unless otherwise specified, the published data com-
prises typical values for the 761 SD Compact IC at an
ambient temperature of 25 °C.
7.1.1 Conductivity
measurement
Measurement range 1
0
…
1000
µ
S/cm (resolution: 0.56 nS/cm)
Measurement range 2
0
…
250
µ
S/cm (resolution: 0.14 nS/cm)
Measurement range 3
0
…
50
µ
S/cm (resolution: 0.028 nS/cm)
Maximum error
±
1 % of full scale value and
±
1 % of measurement value (k = 16.7/cm)
Linearity
Deviations <
±
0.5 % of full scale value
Noise
Measurement
range
1
Measurement
range
2
Measurement
range
3
typ. 10 nS/cm
typ. 2.5 nS/cm
typ. 0.5 nS/cm
Drift (electronic)
typ. < 10 ppm/h of full scale value
Temperature dependence
typ. < 40 ppm/°C of full scale value
Reserve range
> 33 % (k = 16.7/cm)
Sampling rate
10 measurements/s (fixed)
7.1.2 Conductivity
detector
Construction
Thermostatted conductivity detector with
2 ring-shaped steel electrodes
Measurement principle
Alternating current measurement with 1 kHz fre-
quency and ca. 1.7 V amplitude (peak to peak).
Cell volume
1.5
µ
L
Cell constant
approx. 17 /cm (the exact value is printed on the
detector)
Maximum back pressure
for measuring cell
5.0 MPa (50 bar)
Thermostatting
Connectable dynamic control to adjustable oper-
ating temperature
Operating temperature
Adjustable in steps of 5°C from 25
…
45°C