Wide Range Oxygen Probe with Analog Output

OXYBase® WR-RS485-AO

The OXYBase® WR-RS485-AO combines an optical sensor type PSt3 and electro-optical module in one probe. The sensor has a maximum measurement range of 0 - 100 % O2, and a detection limit of 0.03 % O2 / 20 ppb. As it is waterproof, this probe is ideally suited for e. g. measurements in aquaculture or environmental research projects. OXYBase® is connected directly to the control unit, uses RS485 as digital interface (PreSens proprietary) and has 4 - 20 mA analog output. A serial communication protocol is offered for data exchange between the OXYBase® and a PC or other host unit. For initial operation and adjustment of the 4 - 20 mA output the PreSens EOM-STS software can be used. The probe is available with various cable lengths, and its sensor is integrated in a removable sensor cap (OEC), which can easily be exchanged. These exchange caps are offered in different versions for certain demands (fast response time, safe for food applications, for aggressive environments, USP Class VI compatible). The sensor is not autoclavable.

  • Maximum measurement range of 0 - 100 % O2, detection limit 0.03 % O2
  • Ideal for e. g. environmental research, aquaculture, sewage
  • Waterproof
  • Communication via RS485 (PreSens proprietary)
  • 4 - 20 mA analog output
  • Available with various cable lengths


Oxygen Monitoring in Aquaculture

OXYBase® are the solution to control dissolved oxygen in aquaculture. The robust probes can be connected to control units so ideal water conditions can be assured, thus also helping to increase yield. OXYBase® are real low-maintenance probes, as a used sensor can simply be replaced by changing the OEC at the probe tip.

Biological & Environmental Research

OXYBase® are long-term stable probes that can be implanted in soil or other samples for prolonged time periods. They are ideally suited for long-term monitoring of e. g. soil aeration processes, which are very critical for plant productivity, or dissolved oxygen measurements in water samples.


SpecificationsGaseous & Dissolved O2Dissolved O2
*at 20 °C, 960 - 980 hPa; humidified gas mixtures
**after customized calibration
***determined changing from 20.9 % oxygen gas to nitrogen 5.0
****determined changing from air-saturated water to a freshly prepared 1 % sodium sulfite solution
Measurement range*Optimal: 0 - 50 % O2, 0 - 500 hPa
Max.**: 0 - 100 % O2, 0 - 100 hPa
Optimal: 0 - 22.5 mg/L
Max.**: 0 - 45.0 mg/L
Limit of detection*0.03 % O2, 0.3 hPa 0.020 mg/L
Resolution*1 % O2 ± 0.02 % O2, 20.9 % O2 ± 0.1 % O20.4 mg/L ± 0.009 mg/L, 9 mg/L ± 0.04 mg/L
Response time (t90)< 10 sec.***< 30 sec.****
CompatibilityAqueous solutions, ethanol, methanol, cleaning agents containing ClO2 at room temperature
No cross-sensitivity topH 1 - 14, CO2, H2S, SO2, ionic species
Cross-sensitivity toOrganic solvents such as pure acetone, toluene, chloroform or methylene chloride
Chlorine gas
Cleaning procedure3 % H2O2, acidic agents (HCl, H2SO4) max. 4 - 5 %
Cleaning agents containing ClO2 at room temperature
CalibrationTwo-point calibration in oxygen-free (e. g. nitrogen 5.0, 1 % sodium sulfite solution) and air-saturated environment (20.9 % oxygen, air-saturated water)
Storage stability of sensor cap5 years provided the sensor material is stored at room temperature in dry conditions and in the dark
Sampling rate1 sec. up to 9 min. 59 sec.
Temperature sensorNTC
Temperature performanceAccuracy < ± 1 °C
Power supply7 - 30 VDC
Power consumption in active modeMax. 1 W
Power consumption in stand-by mode< 0.15 W
Temperature range operationOptimal: 0 °C to + 40 °C
Max.: - 10 °C to + 70 °C
Temperature range storageOptimal: room temperature (+ 20 °C ± 5  °C)
Max.: 0 °C to + 70 °C
Pressure resistance*3 bar
DimensionsProbe length: 135 mm, diameter: 12 mm; various cable lengths
Probe housing materialStainless steel SUS 316 L
Weight100 g
Digital interfaceRS485 (PreSens proprietary)

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