Automatic Total Oxygen Demand (TOD) Analyzers
Toray’s TOD automatic analyzers rapidly and accurately perform automatic analysis of total oxygen demand in rivers, lakes and marshes, sea areas and plant discharge, both online and offline.
These TOD meters measure concentration differences using a zirconia solid electrolyte sensor developed by Toray, capable of producing high-precision, high-stability results over a long period of time. These innovative devices are economically priced, based on our over four decades of technology and usage track record, and even easier to operate, more reliable, and easier to maintain.
- Oxygen concentration difference measurement method, which is minimally affected by external factors, makes high-precision, long-term, high-stability measurement possible
- Detectors use highly reliable special zirconia sensors
- Don’t require expensive test reagents. Easy to maintain and manage
- Can be used to perform stable measurement of seawater samples
- 6 streams can be measured by each unit. Offline measurement is also possible
- Can be used with various samples when combined with different preprocessing devices
- River, lake and marsh, sea area, and plant discharge water quality management
- Source measures, leak detection, rainwater stream monitoring
- Drainage treatment equipment operation management, verification, and evaluation
- Automatic measurement devices for total water quality emissions regulation compliance
Principle of Measurement
Toray’s TOD automatic analyzers use nitrogen as a carrier gas, drawing in oxygen in the gas mixing section and maintaining a constant concentration.
The carrier gas driven sample measurement section, which is equipped with a self-cleaning function, uses platinum catalyst to combust constant amounts of sample in a combustion chamber at a temperature of 900°C.
Moisture is removed from the measurement gas that flows out of the combustion chamber using a dehumidifier.
In order to prevent external factors from affecting measurements and perform long-term, stable measurement, these devices use a solid electrolyte oxygen detector, determining TOD values by measuring the difference in oxygen concentration between two gas flows.
|Stream switching function||2-6stream*3|
|Measurement cycle||5–10 min|
|Measurement method||Automatic intermittent sealed combustion - oxygen concentration difference detection method|
|Calibration method||Span calibration: Manual
Zero calibration: Manual (With auto zero function)
|Washing||Automatic washing of injection tube and combustion section; Alternate injection of sample and washing liquid (Washing liquid contained in the unit)|
|Range setting||Manual switching, automatic switching driven by external signal|
|Type||Standalone console, with casters|
|Weight||Approx. 180 kg|
|Standard liquid||Potassium hydrogen phthalate aqueous solution|
|Repeatability||Within ±2.5% of full scale|
|Zero stability||Within ±2.5% of full scale/day|
|Span stability||Within ±2.5% of full scale/day|
|Ambient temperature change||Within ±2.5% of full scale/5°C|
|Measurement value output||External output: DC 4–20 mA (Option)
Range ID signal no-voltage contact: AC 125 V, 0.05 A
|Error alarm indication||LED display, Closed contact output in case of error (AC 125 V, 1 A)|
|Alarms||Heater temperature control
Gas mixer error
Out of carrier gas
Carrier gas pressure drop
Out of washing water (Option)
|Sample conditions||Online measurement: 0.02–0.15 MPa, 500 ml/min or higher
Offline measurement: Normal pressure, 100 ml/3 times
|Reagents/Utilities||Washing liquid: Distilled water
Carrier gas: Nitrogen gas, Pressure 0.3 MPa
Consumption: 8 Nm3/month
|Power||AC100V±10V 50/60Hz Approx. 600VA|
|Set up conditions||Indoors
3–40°C during operation (Temperature gradient 10°C /hour or less)
45–85%RH (No condensation)
Specifications are subject to change due to product improvements.
* 1 Only one of these can be selected.
* 2 A separate dilution unit (ADU-600) is necessary to add the dilution function.
* 3 A separate stream switching unit (VSS-206) is necessary to add the stream switching function. Please designate the necessary streams before determining specifications.
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