R-404a
Gas | Refrigerant |
Formula | R-404a |
Group | HFC |
Appearance | Colorless Odorless |
Personal hazards | Displaces oxygen |
Environmental hazards | Greenhouse gas |
Operational risks | Interruption of the cold chain |
The ME1250 gas sensor is a remote measuring unit for monitoring the concentration of refrigerant in surrounding air. Refrigerants are generally non-toxic, but can endanger people due to their oxygen-displacing properties. The sensor is used as a leak detector for personal protection and for alarms in refrigeration systems in order not to interrupt the cold chain.
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-R404A-13 | 1250-R404A-13 |
---|---|---|
Description | Gas Sensor ME 1250 Refrigerant R-404a Bus communication | Gas Sensor ME 1250 Refrigerant R-404a 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 | < 1.9 W | < 2.5 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-HAL-832 | Measuring cell for refrigerant/chloroform | up to 3 years |
Gas concentration
- The measuring cell can react to larger fluctuations in humidity
- Exposure above 800 ppm requires recalibration
- High exposure can destroy the measuring cell
Cross sensitivity
Due to the measuring method, all hydrocarbon compounds are detected. If different gases are to be expected, calibration should be made to the substance for which the sensor has the lowest sensitivity.