Shallow Water H₂ Probe
Measurement of dissolved hydrogen concentrations
The H2 probe was developed for in situ measurement of changes in dissolved hydrogen concentrations in natural and industrial waters.
Mounted on multi-parameter systems such as CTD probes, this sensor is composed of a waterproof connector, a probe body incorporating an electronic signal transformation card and a micro H2 sensor installed at the tip.
The amperometric measurement allows fine and fast measurements, approximately 2 seconds for 90% of the measurement even for concentrations of the order of a few micrograms, moreover the turbidity and the color of the water have no influence. on measure.
For the determination of dissolved H2 concentrations, the data from the probe must be combined with a temperature measurement of the sample or medium.
The equipment is delivered with the slope of the sensor (electrode) calculated at calibration, as well as the temperature compensation data and calculation formulas to obtain the hydrogen concentration in mg / l. The exchange of the micro sensor installed at the tip is very simple and can be done by the user directly.
The shallow water H2 probe also allows the integration of a micro O2 sensor for dissolved oxygen measurements, replacing the micro H2 sensor.
Measurement principle
The dissolved hydrogen passes through the gas permeable membrane. It diffuses to the working electrode where an electrochemical oxidation reaction takes place. The current generated, proportional to the partial pressure of dissolved hydrogen, is measured by the probe.
This current of 0 to 400 pico-amperes is then converted by the electronic card in the probe body into an analog signal of 0 to 3 VDC.
Applications
- Monitoring and protection of wastewater networks
- Start-up control of power plants
- Industrial process management
- Monitoring of the natural environment
- Closed circuit H2 dosage
Advantages
- Measurement without sampling directly in the medium
- No interference with turbidity or water color
- Maximum immersion depth 100 meters
- Analog output signal without external controller
- Waterproof SubConn connector
| Measuring principle | amperometric |
|---|---|
| Measuring ranges | - type I: 0.0002 ... 0.5 mg / l H₂ - type II: 0.0004 ... 1 mg / l H₂ - type III: 0.0008 ... 2 mg / l H₂ - type IV: 0.001 ... 3 mg / H₂ |
| Measurement resolutions | - type I: 0.1 µg / l H₂ - type IV: 0.4 µg / l H₂ |
| Measurement accuracy | 2% of the measured value |
| Response time | T90% 2 seconds |
| H₂ consumption | negligible |
| Materials | titanium (probe body), silicone (membrane), glass (electrode), epoxy resin |
| Dimensions (d x L) | 24 mm x 235 mm |
| Power supply | 9 ... 30 VDC |
| Consumption | NS. 0.5 mA at 12 VDC, approx. 0.25 mA for 24 VDC |
| Output signal | analog 0 ... 3 VDC |
| MS08 power supply | subConn BH-4-MP |
| Micro H2 sensor lifespan | 6 months in portable use, 10 months continuously (depends on stress by pH variations) |
| Interference on measurement | no interference in salt water up to 40 g / l salt |
| Sensitivity to H2S | can lead to measurement errors and / or a reduction in the life of the micro sensor |
| Maintenance | cleaning the measuring membrane with distilled water after each use |
| Temperature of the medium / sample | 0 ... + 30 ° C (40 ° C possible with a specific calibration on request) |
| Ambient temperature | 0 ... + 40 °C |
| Storage temperature | 0 ... + 40 °C |
| Storage temperature | 0 ... + 40 °C |
Control unit
msBox
Universal transmitter
Plug-and-play installation
