4
O&M Manual
Rev-J (11/18)
Part 1 - Introduction
1.1
General
The Model Q46H/65 is a versatile on-line monitoring system designed for the continuous
measurement of chlorine dioxide in solution. The full scale operating range of the system may be
selected by the user for 0-200.0 ppb, 0-2.000 ppm, 0-20.00 ppm, or 0-200.0 ppm, and the
sensing system will operate on water streams with temperatures ranging from 0 to 55
C. The
Q46H/65 ClO
2
Measurement System is well suited for potable water systems, cooling tower
monitoring, food wash water systems, or other ClO
2
treated water applications.
The basic sensing element used in the chlorine dioxide monitor is a polarographic membrane
sensor which measures dissolved ClO
2
directly. Water simply flows past the sensor and directly
to drain, with the flow rate and pressure across the sensor controlled by a constant head flow cell
assembly. The chlorine dioxide measurement does not alter the sample or add any chemicals to
the sample stream, so the water flow can return to the system if desired.
Q46H/65 Monitors are available in two basic electronic versions, a 90-260VAC powered monitor,
or a 12-24VDC powered monitor
– both with three relays and two 4-20 mA analog outputs. Both
versions allow flexible output options which include an additional 4-20 mA current output,
additional 0-30V signal relays, PID control, and digital communication cards.
In addition to chlorine dioxide measurement, the Q46H/65 is also available with an optional pH
input which provides a two-parameter monitoring system. Both dissolved ClO
2
and pH are
displayed simultaneously, and outputs are available for both chlorine dioxide and pH.
Digital communication options for Profibus-DP, Mobus-RTU, and Ethernet-IP are supported in the
Q46 series of products. If your monitor contains a communication card, a separate manual is
provided for that protocol. Consult that manual for information regarding wiring requirements for
your system.
