AsH3
Gas | Arsenic Hydride Arsine |
Formula | AsH3 |
CAS number | 7784-42-1 |
Max. workplace concentration | 0.1 ppm |
Relative density | 2.691 |
Appearance | Colorless Unpleasant smell or garlic |
Hazards | Blood poison (dissolves red blood cells) |
The ME1250 Gas Sensor is a remote measuring unit for monitoring gas concentration and is used as a leak detector.
The microprocessor-controlled electronics of the sensor, adapted to the specific properties of the measuring cell, enable fast and reliable signal processing. The measured gas con-centration is transmitted to a Gas Control Panel, which can manage a large number of distributed gas sensors.
Thanks to bus communication, only one cable is required, which can be continued from sensor to sensor. The ME 1250 Gas Sensor is also available with an analogue output signal of 4…20 mA. The measured gas concentration can thereby be processed by other PLC (Programmable Logic Controllers).
The optional relay module expands the ME 1250 Gas Sensor internally with 3 relays for direct switching of signal transmitters without the use of a control panel.
Advantages
- Automatic zero point calibration
- Active noise reduction on the measurement signal
- Linear measurement signal depending on the gas concentration
- High response sensitivity with short response time
- Selective and reliable measurement with a stable measurement signal and zero point
- Temperature-compensated measurement signal
- Long service life
Technical Specifications
Versions
Article code | 12BUS-ASH3-10 | 1250-ASH3-10 |
---|---|---|
Description | Gas Sensor ME 1250 AsH3 Arsenic Hydride Bus communication | Gas Sensor ME 1250 AsH3 Arsenic Hydride Analogue |
Output signal | Bus communication with gas control panel | Analogue 4…20 mA Load max. 800 Ω at 24V input |
Connection | 4-core cable U72M 1x4x0.6 mm Shielded | 3-core cable U72M 1x4x0.6 mm or CY 0.5 mm2 Shielded |
Topology | Bus, tree or star topology | Star topology |
Power | < 0.15 W | < 0.8 W |
Signal Processing
Accessories
Article Code | Description |
1250-REL | Relay module for single sensor ME 1250 |
1250-AIR-BOX | Ventilation duct add-on box for gas sensor ME 1250 |
1250-AIR-FLOW | Fitting hose connection for gas sensor ME 1250 |
1250-SUP | Mounting plate round pillars for gas sensor ME 1250 |
1250-SCHUTZ | Sun and weather protection for gas sensor ME 1250 |
Consumables
Article code | Description | Lifespan |
---|---|---|
CELL-ASH3-C1 | Measuring cell for arsenic hydride | up to 2 years |
Gas concentration
- Exposure above 1 ppm requires recalibration
- Exposure above 5 ppm can destroy the measuring cell
Cross sensitivity
Gas | Concentration | Reading |
---|---|---|
Ethene C2H4 | 20 ppm | 0 ppm |
Carbon Monoxide CO | 200 ppm | < 0.5 ppm |
Chlorine Gas Cl2 | 20 ppm | -4 ppm |
Fluorine F2 | 7.7 ppm | < -0.9 ppm |
Hydrogen H2 | 1,000 ppm | 0 ppm |
Hydrogen Sulfide H2S | 20 ppm | ~ 21 ppm |
Hydrogen Chloride HCl | 20 ppm | < 0.1 ppm |
Hydrogen Fluoride HF | 10 ppm | 0 ppm |
Isopropanol C3H7OH | 1,000 ppm | 0.25 ppm |
Methanol CH3OH | 960 ppm | < 0.1 ppm |
Nitric Oxide NO | 35 ppm | < 2 ppm |
Nitrogen Dioxide NO2 | 5 ppm | -1 ppm |
Monophosphine PH3 | 1 ppm | 0.53 ppm |
Sulfur Dioxide SO2 | 5 ppm | 1 ppm |
Monosilane SiH4 | 10 ppm | 0.6 ppm |