Thermo Fisher Scientific ECCS10-0-1S User Manual

Instruction Sheet

Conductivity / Resistivity Sensors

(ECCS10-0-01S / ECCS10-0-01T / ECCS10-0-1S / ECCS10-1-0S)

Copyright © 2006 All rights reserved.
Eutech Instruments Pte Ltd

Blk 55, Ayer Rajah

Crescent, #04-16/24
Singapore 139949

[phone]

[phone] fax

www.thermofisher.com

CONDUCTIVITY/RESISTIVITY CELL

Simple conductivity sensors are constructed of an insulating material imbedded with graphite, platinum,
stainless steel or other metallic pieces. These metal contacts serve as sensing elements and are placed at
a fixed distance apart to make contact with a solution whose conductivity is to be determined. The
distance between the sensing elements as well as the surface area of the metallic piece, determine the
cell constant, defined as length/area. The cell constant is a critical parameter affecting the conductance
value produced by the cell and handled by the electronics circuitry.

A cell constant of 1.0 will produce a conductance reading approximately equal to the solution
conductivity. For solutions of low conductivity, the sensing electrodes can be placed closer together,
reducing the distance between them and producing cell constants of 0.1 or 0.01. This will raise the
conductance reading by a factor of 10 to 100. Sensing electrodes can be placed further apart to create
cell constants of 10 or 100 for use in highly conductive solutions. This also produces a conductance
acceptable to the meter by reducing the conductance reading by a factor of 10 to 100.

In order to produce a measuring signal acceptable to the meter, it is highly important that the user
chooses a cell with a cell constant appropriate for the sample. The table below lists the optimum
conductivity range of cells with different cell constants.

Order Code Cell constant Optimum Conductivity Range Cell Material

ECCS10-0-01T 0.01
ECCS10-0-01S 0.01

ECCS10-0-1S 0.1

0.055 – 20 μS/cm (Ultra-Pure Water)

0.055 - 20 μS/cm

0.5 - 200 μS/cm

Titanium

SS 316
SS 316

ECCS10-1-0S 1.0 0.01 - 200 mS/cm SS 316

NB: All above cells have integrated Pt 100 ATC sensor. When used in “Pure Water” applications, select cells
with cell constants, k = 0.01, and select in “temperature coefficient” option, “Pure Water Compensation”,
available in CONCTP1001/2, RESCTP1001/2, CONCTP2000P and CONCTP2000W.

OPERATING INSTRUCTIONS

Before use, rinse the cell in 50% Isopropanol to remove oil film. Connect the cell to the meter and follow
the meter instruction for standardizing the cell for use at a given temperature. Rinse the cell sensing
elements with distilled or deionised water between samples. The cell constant may change slightly with
use and should be calibrated to the user’s meter.

CLEANING & STORAGE

The single most important requirement of accurate and reproducible results in conductivity
measurements is a clean cell. A dirty cell will contaminate the solution and cause the conductivity to
change. Grease, oil, fingerprints, and other contaminants on the sensing elements can cause erroneous
measurements and sporadic responses.

Clean cells with detergent and/ or dilute nitric acid (1%) by dipping or filling the cell with cleaning
solution and agitating for two or three minutes. Other diluted acids (e.g. sulfuric, hydrochloric, chromic)
may be used for cleaning except for aqua regia. When a stronger cleaning solution is required, try
concentrated hydrochloric acid mixed with 50% Isopropanol. Rinse the cell several times with distilled or
deionised water and re-calibrate with meter.

CONDUCTIVITY/ RESISTIVITY OF VARIOUS AQUEOUS SOLUTIONS AT 25°C

Application Conductivity Resistivity

Pure water

Power plant boiler water

Distilled water

Deionised water

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0.05 μS/cm 18 MΩ-cm

0.05 – 1 μS/cm 1-18 MΩ-cm

0.5 μS/cm 2 MΩ-cm

0.1 – 10 μS/cm 0.1 – 10MΩ-cm