Envco – Environmental Equipment

The Oxi 1970i Portable Dissolved Oxygen Meters ship complete with NiMH rechargeable batteries, dual-voltage 110/220 VAC adapter, and neck strap. A DO probe is not included with the portable dissolved oxygen meters. Choose from one of the two waterproof DO probes listed below or call us if you need a special purpose electrode for your portable dissolved oxygen meter.

FEATURES:
• Waterproof rubberized rugged housing
• Record readings to the built-in memory
• Doubles as a laboratory bench top DO meter

TA 197 Oxi deep water dissolved oxygen probe
The Oxi 1970i Portable Dissolved Oxygen Meters are great for measurements in bore holes (down to 2" diameter), wells and deep bodies of water with the ability to take measurements down to 330 ft (100 m) in combination with the TA 197 Oxi depth armature. The TA 197 Oxi submersible dissolved oxygen probe includes up to 330 feet (100 m) cable with waterproof plug (IP 67), pressure-resistant steel armoring with screw-off protective hood, and is pressure-resistant to 145 psi (10 bar).

CellOx® 325 Dissolved Oxygen Probe
The CellOx® 325 dissolved oxygen probe is a membrane covered galvanic oxygen sensor which offers the following technical advantages:
• Temperature compensation
• Up to 6 months usage of membrane
• High signal resolution
• Rapid response
• Waterproof sensor up to 29 psi (2 bar)
• Membrane leakage monitoring

What is Dissolved Oxygen?
Some oxygen is dissolved in practically every liquid. For example, at a temperature of 68 °F (20 °C) and an atmospheric pressure of 1013 mbar saturated water contains about 9 mg/l oxygen. Ethanol can contain up to 40 mg/l whereas glycerol only has about 2 mg/l.

Each liquid takes up oxygen until the partial pressure of oxygen in the liquid is in equilibrium with the air or gas phase in contact with it. The actual oxygen concentration depends on a number of factors, such as temperature, air pressure, oxygen consumption by microorganisms in a biodegradation process or oxygen production by algae, etc.
The oxygen concentration is important for the:
• Living conditions for fish and microorganisms in waters
• Degradation processes in wastewater treatment
• Corrosion processes in pipelines
• Shelf life of beverages, etc.
The determination of the dissolved oxygen concentration was formerly carried out by the WINKLER titration method. Today electrochemical measurement is a recognized method in numerous standard procedures.

In its simplest form a dissolved oxygen sensor contains a working electrode and a counterelectrode. Both electrodes are located in an electrolyte system which is separated from the sample by a gas-permeable membrane. The working electrode reduces the oxygen molecules to hydroxide ions. In this electrochemical reaction a current flows from the counterelectrode to the working electrode. The more dissolved oxygen present in the sample, the larger the current signal. The dissolved oxygen meter calculates the oxygen concentration in the sample from this signal.

Portable Dissolved Oxygen Meters Specifications
Portable Dissolved Oxygen Meter Range (w/CellOx 325)
O2 Concentration: 0.00 to 19.99 mg/l, 0.00 to 90.0 mg/l
O2 Saturation: 0 to 199.9%, 0 to 600%
Temperature: 32 to 122°F (0.0 to 50°C)
Portable Dissolved Oxygen Meter Resolution
O2 Concentration: 0.01,0.1
O2 Saturation: 0.1,1
Temperature: 0.1
Portable Dissolved Oxygen Meter Accuracy
O2 Concentration: ± 0.5 % of measured value at ambient temperature of 41 to 86 °F (5 to 30 °C)
O2 Saturation: ± 0.5 % of measured value when measuring in the range of ± 10 K around the calibration temperature
Temperature: ±0.1
Temperature Compensation: Accuracy better than 2 % at 32 to 104 °F (0 to 40 °C)
Salinity Compensation: 0 to 70.0 SAL
Air Pressure Compensation: Automatic through integrated pressure sensor in the range 500 to 1100 mbar
Datalogging: 800 data sets
Output: RS-232 with adjustable baud rate
Display: Multi-line LCD
Power: Rechargeable Nickel-cadmium battery or 110/220 VAC adapter
Battery life: Up to 600 hrs
Dimensions: 3.5x7.9x7.5in (90x200x190mm)
Weight: 3.3lb (1.5kg) without plug-in power supply)
IP Rating: IP 67
Certifications: CE

CellOx® 325 Probe
Electrode material: Gold (Working), Lead (Counter)
Shaft material: POM
Cable length: 4.9 ft (1.5 m)
Measuring range: 0 to 50 mg/l O2, 0 to 600% O2
Temperature range: 32 to 122 °F (0 to 50 °C)
Min/max immersion depth: 2.4in to 65ft (6cm to 20m) depending on cable length
Shaft length: 7.38 in (187.5 mm)
Diameter: 0.70 in (17.5 mm)
Weight: 6 oz (170 g)

TA 197 Oxi Submersible Dissolved Oxygen Probe
Measuring principle: Membrane covered galvanic sensor
Temperature compensation: IMT
Range: 0 to 50 mg/l O2
Drift: ~3%/month
Temperature range: 32 to 122 °F (0 to 50 °C)
Pressure resistance: 145 psi (10 bar) max.
Body materials: Stainless Steel (1.4571) & Epoxy
Cable lengths: 25 m, 40 m, 60 m, 100 m
Immersion depth: Min. 2.4 in (6 cm), Max. 330 ft (100 m)
Dimensions: (1-1/2 in dia. x 9-5/8 in L (38 mm dia. x 245 mm L) (overall)
Weight: 36 oz. (1,113 g) sensor & hood w/o cable

Ordering Information
Oxi 1970i Portable Dissolved Oxygen Meter w/universal power supply DO electrode not included.

Portable Dissolved Oxygen Meter Electrodes
CellOx® 325 Portable Dissolved Oxygen Meter Probe Includes 5 ft (1.5m) cable.

TA 197 Oxi-25 Portable Dissolved Oxygen Meter Probe
Deep water dissolved oxygen probe w/82 ft (25 m) cable.

TA 197 Oxi-40 Portable Dissolved Oxygen Meter Probe
Deep water dissolved oxygen probe w/131 ft (40 m) cable.

TA 197 Oxi-60 Portable Dissolved Oxygen Meter Probe
Deep water dissolved oxygen probe w/197 ft (60 m) cable.

TA 197 Oxi-100 Portable Dissolved Oxygen Meter Probe
Deep water dissolved oxygen probe w/328 ft (100 m) cable.