OxyGuard CO2 Portable

The OxyGuard CO2 Portable is a reliable and easy to use instrument that measures the free dissolved carbon dioxide concentration directly in the water. The CO2 concentration is shown on the display, and there is an analogue output. A version with build-in data logger is available.

The OxyGuard CO2 measures the free dissolved CO2 directly and is not affected by carbonates or other dissolved substances. It is the free dissolved CO2 – in other words, the CO2 gas partial pressure, that affects the fish.

The analyser is easy to calibrate using the front panel "slope" and "zero" adjustments – after which you just put the probe in the water and measure. Calibration intervals are long, and the OxyGuard CO2 does NOT need regular maintenance.

Technical Advantages


The OxyGuard CO2 Portable Dissolved CO2 Analyser consists of a probe and battery powered transmitter. The latter has a display and an analogue signal as output. The probe is, as standard, delivered with a 3m cable. The transmitter has an on/off switch, "slope" and "zero" adjustments. Also included are a batter charger, and calibration accessories, i.e. calibration beaker with stirrer, calibration fluid, calibration conditioner and dosing syringe.

Principle of Operation

The probe measures the carbon dioxide content of the water directly by detecting the carbon dioxide partial pressure in the water. It is immportant to note that it is NOT based on a pH measurement – it does NOT detect any change in pH that carbon dioxide causes. Neither does it withdraw a sample for analysis – it detects the free dissolved CO2 –the carbon dioxide partial pressure – in the water

The range of the instrument is 0-50mg/l. Before use the system is calibrated at zero and span. Calibration is carried out using the calibration fluid delivered with the system, dissolved in distilled water that has been treated with the calibration conditioner.

The OxyGuard CO2 Portable Dissolved CO2 Analyser can be ordered with or without a data-logger. The logger can record 15,000 values and has an output for connection to a PC, permitting both recorded values and immediate measurements to be stored and observed.


OxyGuard CO2 Portable

Size: Probe: 40mm dia. x 140mm. Cable length: 3m.
Meter: 300x215x83 mm (overall with carrying handle)
Calibration beaker: 65mm dia. x 260mm
Weight: Approximately 6kg including charger, calibration fluid, calibration conditioner, calibration beaker, and dosing syringe.
Supply (to charger): 230VAC (115VAC on request)
Range: 0-50 mg/l dissolved carbon dioxide.
Temperature compensated range - 3-25°C
Output: Analogue Signal 0-1VDC
Operating Conditions: Electronics -10°C to +60°C, splashproof.
Accuracy: Depends on calibration. Practical accuracy up to ± 1 mg/l.
Response Time: Typically 5 minutes at 20°C depending on flow velocity past probe. In stilkl water, up to 15 minutes.
Flow Requirements: The instrument does not use carbon dioxide for its measurement, but a certain flow is necessary to ensure that the sensing element of the probe is in equilibrium with the surrounding water, and to avoid "spot" measurements.
Operating Time: Approximately 50 hours on fully charged batteries.
DeliveryComprises:Transmitter & probe with 3m cable, charger, analogue output lead,calibration beaker with stirrer & magnet, 75g calibration conditioner, 100ml calibration solution, dosing syringe, measure, screwdriver.

Ordering Information

G02C2P: OxyGuard CO2 Portable Dissolved CO2 Analyser – probe with 3m cable, transmitter and calibration accessories. Charger for 230VAC, other voltage on request. Calibration accessories comprise beaker with stirrer & magnet, 80g calibration conditioner, 100ml calibration solution, and dosing syringe.

G02C2PLOG: As above but with 15,000 cell data-logger built into analyser. Permits storage of values and on-line viewing of values on PC.

G02XCS 100ml Calibration solution.

2XCT 80g Calibration conditioner.