Datasheet

JUMO GmbH & Co. KG
Delivery address: Mackenrodtstraße 14
36039 Fulda, Germany
Postal address: 36035 Fulda, Germany
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Internet: www.jumo.net
JUMO Instrument Co. Ltd.
JUMO House
Temple Bank, Riverway
Harlow, Essex CM 20 2DY, UK
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Internet: www.jumo.co.uk
JUMO Process Control, Inc.
6733 Myers Road
East Syracuse, NY 13057, USA
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Internet: www.jumousa.com
V2.00/EN/00541512
Page 6/18Data Sheet 202552
20255200T10Z002K000
Measurement ranges/cell constants
This modern instrument features a much higher dynamic range on the input side than
conductivity cells are able to control physically or chemically. The measurement range of the
instrument must therefore be coordinated with the operating range of the cell.
Sample measuring ranges for combinations with two-electrode cells
Example
To conduct a measurement in the range from 10 µS/cm to 500 µS/cm,
select a conductivity cell with a cell constant K = 0.1 1/cm.
Configure the unit µS/cm on the instrument without places after the decimal.
Combination with four-electrode cells and two-electrode cells with cell
constant differing from the grid above
This case requires a more in-depth use of the instrument technology. Both the uncompensated
and the temperature compensated measurement scope must be considered.
The uncompensated measurement scope of the instrument may be calculated according to the
following formula:
Measurement scope = 0.1µs/cm × cell constant (K) to 2500 mS × cell constant (K).
After consideration of the temperature compensation range, approximately the following
compensated measurement scope remains:
Measurement scope = 0.1µs/cm × cell constant (K) to 1250 mS × cell constant (K).
It may be assumed that the measurement scope of the instrument is always greater than the
recommended or practically usable range of the conductivity cell that is used.
The smaller range (instrument or conductivity cell) determines the maximum usable range.
Example
What measurement scope can the instrument cover with a specified cell constant?
The specified cell constant is K = 0.4
The measurement scope of the instrument = 0.1 µS/cm × 0.4 1/cm to 1250 mS/cm × 0.4 1/cm
➝ 0.04 µS/cm to 500 mS/cm
Cell constant (K) Recommended/practical measurement scope
(depending on the conductivity cell)
0.01 1/cm 0.05 µS/cm to 20 µs/cm
0.1 1/cm 1 µS/cm to 1000 µs/cm
1.0 1/cm 0.01 mS/cm to 100 ms/cm
3.0 1/cm 0.1 mS/cm to 30 ms/cm
10.0 1/cm 0.1 mS/cm to 200 ms/cm
Cell constant (K) Measurement scope based on instrument
(temperature-compensated)
0.01 0.001 µS/cm to 1.25 ms/cm
0.1 0.01µS/cmto12.5ms/cm
1.0 0.1 µS/cm to 125 ms/cm
3.0 0.3 µS/cm to 375 ms/cm
10.0 0.1 mS/cm to 1250 ms/cm