GENEQ > Environnement > Oxygène dissous - transmetteurs
| Transmetteur optique d'oxygène dissous |
modèle D-OPTO |
| Optical dissolved oxygen sensor and optical DO analyzer |
Features |
| • Accurate with good long term stability • Low maintenance, long calibration interval • Flow insensitive technology, completely unaffected by water velocity • Built in bio-fouling control • No consumables - long sensor life • Low power consumption • Simple to integrate and operate • SDI-12 or 4-20mA versions available |
| Optical Dissolved Oxygen Transmitter Product Description |
The D-Opto Optical Dissolved Oxygen
Transmitter is an instrument designed for measuring dissolved oxygen concentrations
in liquids. The D-Opto Optical Dissolved Oxygen Transmitters were developed
due to the requirements of surface water monitoring programs. The optical
dissolved oxygen transmitter has been specifically designed to meet the
demanding requirements of the environmental monitoring and scientific
research sectors, providing long term, accurate and reliable dissolved
oxygen measurement. The Optical Dissolved Oxygen Sensor has been successfully
used in the wastewater industry for over 10 years and uses field proven
solid state optical sensing technology that is highly stable over long
periods of time, even in harsh conditions. The D-Opto Optical Dissolved
Oxygen Transmitter has extremely low power requirements, and outputs the
data in SDI-12 format making it ideal for incorporation into remote environmental
monitoring installations. Percent saturation values generated by the D-Opto
Optical Dissolved Oxygen Sensors are the percentage saturation that would
occur if the measured liquid were saturated with air under a standard
barometric pressure of 1013 mBar at the same temperature. 4-20mA Optical
Dissolved Oxygen Transmitters are available. |
| Methodology - Optical Dissolved Oxygen Transmitter |
Unlike conventional dissolved oxygen
transmitters, the D-Opto optical dissolved oxygen transmitter's sensing
element utilizes fluorescence to measure dissolved oxygen. The sensing
element in the optical dissolved oxygen transmitter consists of a fluorescing
compound suspended stably in a robust optical “window”. A
light source at controlled wavelength briefly pulses the optical window.
This “excites” the fluorescent material, causing it to emit
a specific wavelength of light. The intensity of this fluorescence or
light is determined by the amount of dissolved oxygen in the water in
contact with the optical window. A highly stable and accurate optical
sensor circuit inside the D-Opto optical dissolved oxygen transmitter
measures the emitted fluorescence. As a result, the optical dissolved
oxygen transmitter provides accurate dissolved oxygen measurements over
long periods of time without the need for re-calibration. |
| Other Dissolved Oxygen Sensors |
Traditional Galvanic and Polargraphic
dissolved oxygen sensors have been used to measure dissolved oxygen in
water. Galvanic and polargraphic dissolved oxygen sensors utilize chemical
electrical signatures based on a semi-permeable membrane covering electrodes
that are immersed in an electrolyte. These dissolved oxygen sensors have
been poorly suited to long term reliable and accurate monitoring of lakes,
streams, and rivers. The semi-permeable membranes and electrolyte require
frequent replacement. The Galvanic and Polargraphic dissolved oxygen sensor
electrodes are subject to deterioration and “poisoning”. These
dissolved oxygen sensors require constant water flow otherwise oxygen
consumption occurs causing inaccurate readings. Galvanic and Polargraphic
dissolved oxygen sensors require frequent calibration resulting in high
upkeep and labor costs. |
| Optical Dissolved Oxygen Transmitter Advantages |
Unlike conventional Galvanic and Polargraphic
dissolved oxygen sensors, D-Opto optical dissolved oxygen transmitters
have no consumable components that require replacement, minimizing servicing
requirments. Neither do the optical dissolved oxygen transmitters consume
oxygen. Consequently the measurement of dissolved oxygen by the optical
dissolved oxygen sensor is unaffected by water flow. The D-Opto optical
dissolved oxygen transmitters can even be deployed in stagnate groundwater
bores. Because of the copper anti-biofoul ring and the general construction
of the optical dissolved oxygen transmitters, they are unaffected by pollutants
and poisons and highly resilient to bio fouling. The D-Opto optical dissolved
oxygen transmitters have extremely stable electronics – a calibration
interval of 1 year is typical. |
The D-Opto optical dissolved oxygen
transmitters can be used to monitor dissolved oxygen in almost any liquid,
including wines, beer, and milk. The optical dissolved oxygen sensors
are not affected by color of the liquid. Bubbles or aeration do not affect
the optical dissolved oxygen transmitters measurements. The optical dissolved
oxygen sensors can also be mounted in process lines for quality assurance. |
Global Water's PC300 Optical Dissolved
Oxygen Controller can use the optical dissolved oxygen transmitter's 4-20mA
output to control pumps or alarms. In addition Global Water offers the
GL500 optical dissolved oxygen recorder which adds recording capabilities
to the 4-20mA optical dissolved oxygen transmitter. The GL500 optical
dissolved oxygen recorder connects to the optical dissolved oxygen sensor's
4-20mA output to record highly accurate dissolved oxygen data. |
| Applications |
• Long term monitoring
of dissolved oxygen in streams, rivers and lakes • Scientific research projects, both long and short term projects • Water quality monitoring around industrial outfall • Homeland security • Thermocline profiling • Fish farm and aquaculture water quality monitoring • Wastewater industry • Food and wine industry |
 |
Close
up of measurement window and copper biofoul ring. |
 |
A sensor being
pulled out after 4 weeks in the drink…. Perfect condition. These sensors are put in a 150mm (6 inch) pipe that is perforated. This prevents growth of foul by removing photosynthesis as a growth influence. This also protects the sensors for debris floating downstream. |
 |
This
sensor was located downstream of a paper mill discharge. Biofoul is always an issue with sensor deployments but the additional contaminates in this stream proved quite difficult. The copper biofoul ring served its purpose and showed that cleaning was only needed every other trip. |
| Optical Dissolved Oxygen Transmitter Specifications |
| Output: SDI-12 or 4-20 mA (with converter) Dissolved Oxygen Accuracy: 1% of reading or 0.02 ppm, which ever is greater Resolution: 0.01% Saturation, 0.001 ppm Range: 0.00 to 25.0 ppm Repeatability: 0.01 ppm Response time: 90% in less than 60 seconds Temperature: Compensated 0 to 50°C Sensor Drift: Less than 1% per year |
| Temperature: Accuracy: ±0.1°C Resolution: 0.01°C Range: 0 to 50°C |
| Depth Rating: Maximum 30m water
depth Operating Voltage: 9-15 VDC Current Draw: 10 mA during measurement, 0.5 mA standby Size of Transmitter: 48mm (1.89”) diameter x 156mm (6.173”) long Transmitter Construction: Acetyl, stainless steel, cast epoxy Weight: 1 lb. Cable: 4 core, 20 AWG, shielded, EPDM jacket |
| Optical Dissolved Oxygen Transmitter Options & Prices | |
| D-Opto Optical Dissolved
Oxygen Transmitter - SDI-12 Includes 25 ft of cable. |
|
| D-Opto Optical Dissolved
Oxygen Transmitter - 4-20mA Includes SDI12 to 4-20mA converter module and 25 ft of cable . |
|
| D-OPTO-CBL Extra Cable for D-Opto Transmitter | |
| RELATED PRODUCTS | |
| 4015 SDI-12 to Analog converter | |
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| DO610 Dissolved Oxygen Probe Kit Measure 6 water quality parameters. |
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| 407510 Dissolved Oxygen Meter Includes probe on 3.9ft cable, 5 membranes, protective holster, 9V battery, and case. |
|
| WQ401 Dissolved Oxygen Sensor | |
| GL500-7-2 Optical Dissolved Oxygen Recorder Optical dissolved oxygen recorder for sensor datalogging. Includes Global Logger Software. With weather proof enclosure and 12V battery. |
 |
| PC300 Optical Dissolved Oxygen Controller | |
| EZ100 Optical Dissolved Oxygen Transmitter Display LCD readout display for both portable use and permanent installations. |
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