| Model | FA-490 |
| Measuring Gas | Combustible gas in the air | Hydrogen in the air | Methane in the air | Organic solvent in the air |
| Detection Principle | Catalytic combustion method (Note 1) | Hot wire semiconductor method (Note 2) | Hot wire semiconductor method (Note 2) | Hot wire semiconductor method (Note 2) |
| Measuring Range | 0 - 100%LEL | 0 - 2,000ppm | 0 - 5,000ppm | 0 - 500ppm |
| Accuracy | Within ±25% of the setting value | Within ±25% of the setting value (within a range of 1000ppm from 200ppm) | Within ±25% of the setting value (within a range of 1000ppm from 500ppm) | Within ±25% of the setting value (within a range of 200ppm from 50ppm) |
| Display Method | 4-digit LED digital |
| Alarm Method | Red LED lights intermittently and buzzer sounds intermittently |
| Alarm Setting | Adjustable (2 step alarm) |
| Failure display | Red LED lights intermittently and buzzer sounds intermittently |
| Power Source | AC100V±10V, 50/60Hz (AC220V as extra option) |
| Alarm contact output | Gas alarm : 1a or 1b contact, Faulty alarm : 1a or 1b contact, AC125V, 0.6A (Resistance load) |
| Analog output | 4?20mA |
| Detection Point | 1 point |
| Operating Temperature Range | Temperature: -10 - 40℃ |
| Installation | Wall mount type (Panel mount type is optional) |
| Dimensions | 120(W)×205(H)×69(D)mm |
| Weight | 0.9kg |