Honeywell 4905 Style Conductivity Cells 70-82-25-18 - Manual (Page 11)

Installation
12/07 4905 Series Conductivity Cells – Installation and Maintenance 5
3. Installation
3.1 Overview
The conductivity cell is secured permanently to the 1” N.P.T. bushing which is used for all types of
mountings. Although the physical appearance of the various cells is the same (except for length), the cell
construction differs according to the constant. On the 10 and 50 constant cells, the electrodes are short
tubes located midway inside the two parallel tubular channels that run lengthwise through the cell, and are
open to the sample at both ends of the cell. The channels are elliptical on the 10 constant cell. The 1, 0.1,
and 0.01 constant cells have a removable cell guard which is screwed onto the cell body to protect the
electrode surfaces. Electrodes are three disks on the 1 constant cell, parallel plates on the 0.1 constant cell,
and wire wound on the cell body on the 0.01 constant cell. Cells must be used with the guard in place or
the cell constant may differ from that specified.
Most of the auxiliary parts which enable the user to achieve the various types of mounting are readily
obtained from local suppliers. For an immersion mounting (only applicable in applications where the
temperature does not exceed 85°C)with 04905 Series cells, only the appropriate length of 1/2 inch pipe
(e.g., CPVC) and if desired, a 1/2 inch end coupling is needed. For an in-line flow mounting, only a 1”
schedule 40 tee is required. The basic cell can be converted to a flow cell for either bypass or in-line
arrangements by use of the PES flow-cell housing (Honeywell Part 276127) shown in Figure 3-2.
However, the temperature and pressure specifications listed for this flow chamber under Specifications
apply.
3.2 Types of Mounting
There are three types of mounting: Flow, Immersion (for use in applications where temperatures do not
exceed 85°C) and Insertion. Mounting dimensions for each type of cell assembly are given in Figure 3-2,
Figure 3-3, and Figure 3-4.
3.3 The Differences between the Quick Disconnect and Integral
Cable Option
The cable options of quick disconnect and integral cable do not affect the performance of the cell. These
options only relate to how the cell is connected to the instrument.
ATTENTION
•There are different electrical connections for these options. Please refer to Section 4 for instructions.
NOTE: The wire colors for the integral cable and quick disconnect option are not the same. Do not use shielded
cable except where shown in the following figures.
• Integral cable means the cable is potted into the cell. The cable and cell are one entity and cannot be
separated.
• The quick disconnect option means the cell is connected to the cell by a receptacle on the top of the
cell. The cell and the cable are separate entities. When the time comes to replace the cell, the cable
does not have to be replaced. The cable can simply be mated with another cell that has the quick
disconnect option. This option cannot be used in immersion applications. The cable must be
purchased from Honeywell.