Danfoss GD Basic fixed gas detection unit, code 148H6045, a factory-calibrated wall-mount detector for R404A / R507A refrigerant in refrigeration machinery rooms, cold stores and process plant. Semiconductor sensing element with a 0–2000 ppm measuring range and two-level alarm relays (pre-alarm 500 ppm, main alarm 900 ppm). Relay outputs drive external alarm panels; no on-board display on this version. Operating temperature -40 to +50 °C. Supplied as a complete unit with mounting kit, cable gland and a factory calibration certificate. Supply 19–29 V DC. Integrates with Danfoss AK-SM system managers and standard alarm panels. HS 9027.10. OEM P/N 148H6045.