Dissolved oxygen monitoring is critical for aeration system process control. Optimization of the biological process, whether it be carbonaceous removal, nitrification or nitrification/denitrification, depends on maintaining proper DO levels. In addition, controlling blowers and aerators to operate at optimal level eliminates excess aeration and will result in large power savings for the plant.
ATI's Series Q45D has been providing reliable DO control in plants throughout the world for many years. Using a galvanic membraned sensor, this system is a proven performer in the most demanding applications.
Now, the Q45D is being upgraded with the addition of a new optical dissolved oxygen sensor that reduces maintenance to a new low. Based on fluorescence quenching technology, this sensor provides continuous DO monitoring with virtually no service and still provides the reliability inherent with the Q45D automatic sensor cleaning system.
Low Maintenance & Reliable Performance - Optical DO sensors developed in the last few years use a technique that essentially measures the rate at which oxygen absorbs an optical signal generated within a membrane impregnated with a fluorescent dye. The dye within the optical element is excited by a pulse of light from an internal LED. This causes the dye to fluoresce or emit light of a different wavelength. The rate at which this emitted light decays (or is quenched) is proportional to molecular oxygen in the element. The higher the oxygen level, the faster the decay rate.
Optical sensor do not have internal electrolyte, so maintenance on this type of sensor is limited to changing the optical element. ATI's optical element is designed to last a minimum of 2 years in normal operation, but will more often provides a life of 3-5 years unless mechanical damage occurs. Optical sensor also do not require flow across the sensor so measurements can be made more accurately in systems with low flows. Unlike some optical sensors, this sensor is not degraded by exposure to sunlight.
The Q45D-ODO Auto-Clean DO system is supplied complete with all measurement and air cleaning components conveniently packaged in a single enclosure. All that's needed for installation is connection of AC power and hookup of the DO sensor cable and sensor air tube. Sensors are mounted to a 1" support pipe with a quick release mounting assembly to allow for easy inspection. Even a separate alarm relay is available to signal operators in the event that the air cleaning system requires attention.
Specifications
| Measurement Type |
Dissolved oxygen |
| Sensor Type |
Optical fluorescence quenching |
| Range |
0-40.0ml/l
0-200% saturation |
Response Time
|
90% in 150 seconds
|
Accuracy
|
±0.05 ppm below 2 ppm
|
Repeatability
|
±0.2 ppm from 2-10 ppm
±0.4 ppm above 10 ppm
|
Electronic Linearity
|
±0.5%
|
Zero Drift
|
<1% of full scale per month, non-cumulative
|
Display
|
Backlit LCD, 0.5" main display
|
Controls
|
4 membrane switches on front of monitor
|
Outputs
|
Two isolated 4029 ma, 575 ohms maximum
|
Alarm Relay
|
Two SPDT, 5A @ 230 VAC resistive
|
Relay Coil
|
Programmable either normally energized or normally de-energized
|
Optional Alarm
|
Cleaner system failure alarm
|
Power
|
115 or 230 VAC, 50/60 Hz, 5 VA max |
Sensor Operating Temperature
|
0 to 50°C
|
Monitor Operating Temperature
|
-20 to 60°C, -40°C with optional heater
|
| Sensor Cable |
30 feet standard |
Humidity
|
0-95%, non-condensing
|
| Weight |
10 pounds
|
Ordering Information
Other configurations available For pricing, please call AFC
International at 1-800-952-3293, 219-987-6825 or fax 219-987-6826 or
email sales@afcintl.com
| Description |
Catalog No. |
Q45 Dissolved Oxygen Monitor, 24 VDC, 2 Wire, Submersible Sensor with 15' cable, 5 mil Membrane, No Heater, No Alarm
|
Q45-1-1-1-1-1
|
Q45
Dissolved Oxygen Monitor, 115 VAC with 2 Relays & Outputs,
Auto-Clean Sensor with air Nozzle & 30' Cable, 5 mil Membrane,
Heater/Thermostat & Cleaner Fail Alarm System
|
Q45-2-3-1-2-2
|
Q45
Dissolved Oxygen Monitor, Portable 9 VDC Battery with 0-2.5 V Outputs,
Submersible Sensor with 15' Cable, 5 mil Membrane, No Heater, No Alarm
|
Q45-4-1-1-1-1
|
Downloads
Q45D-ODO Monitor literature