Gas Alarm GX-D250

GX-D250 CO₂ Alarm: The Smart Professional Ventilation Manager with Text Display and Relays

Fresh air is no coincidence – with the GX-D250 from Elektrotechnik Schabus GmbH & Co. KG, it becomes a habit.

From 800–1000 ppm, the illuminated text display shows “Please ventilate” and emits a soft tone long before anyone feels tired. At 2500 ppm (half the MAK value), the potential-free relay automatically activates forced ventilation or opens ventilation flaps, while the second relay reports faults to the building management system (BMS).

External NDIR infrared sensor with 2.5 m cable – optimally placeable at nose height (higher = less sensitive, lower = more sensitive). Fixed installation, digital signal transmission, long service life, and high precision. Ideal for classrooms, open-plan offices, meeting rooms, and clinics – anywhere clear minds are essential.

The GX-D250 technology is uncompromisingly professional: a high-quality external NDIR sensor with a 2.5 m cable, and two microcontrollers continuously monitor measurement accuracy and cable integrity. Clear text display in German: “Good air”, “Ventilation recommended”, “Please ventilate,” with live ppm reading, temperature, and status.

Pre-alarm from around 1000 ppm with a soft beep, main alarm at 2500 ppm with a louder tone and relay activation. Two potential-free changeover relays: one for ventilation control, one for fault signaling (cable break, sensor error). Thresholds can be adjusted ex-factory. The GX-D250 is not just a detector but an intelligent ventilation management system – documentable, automatable, future-proof.

The GX-D250 is more than a device – it’s the invisible air coach. Whether 30 students in a classroom, 40 colleagues in an open-plan office, or 12 participants in a seminar room: it displays “Ventilation recommended” early on, before headaches or fatigue occur, and automatically activates ventilation at 2500 ppm.

Teachers, facility managers, and employers appreciate the clear text display and relay control – finally, ventilation by plan instead of by guesswork. The flexible sensor placement and German engineering make it a long-lasting solution. It’s the difference between “struggling through the day” and “staying fit until evening.”

The GX-D250 at a glance:

• Text Display: From “Good air” to “Please ventilate” – easy to understand for everyone.
• Dual alarm thresholds: Pre-alarm from 1000 ppm and main alarm at 2500 ppm (half MAK).
• External NDIR sensor: 2.5 m cable – optimal placement at nose height.
• 2 relays: Forced ventilation on alarm + fault signal to building management system (BMS).
• High precision: Two microcontrollers monitor sensor and cable performance.
• Adjustable tone: From subtle to louder – effective without being intrusive.
• Factory adjustable: Threshold levels can be customized.
• Made in Germany: Top quality, service, and longevity from Schabus.

Applications: Where the GX-D250 ensures ideal air quality

The GX-D250 is the intelligent ventilation manager for all professionally used occupied spaces:

• Classrooms & schools: Students stay alert – display shows “Ventilate”.
• Open-plan offices: Automatic ventilation at 2500 ppm.
• Meeting & conference rooms: Clear minds during long sessions.
• Medical practices & waiting rooms: Healthy air for patients and staff.
• Seminar & training rooms: Concentration throughout the day.
• Co-working spaces: Productive air for all users.
• Modern living & home offices: Healthy air, even at home.

With the GX-D250, clean air starts at the display and fatigue stops. It’s the professional, relay-controlled solution for anyone seeking healthier, automatically ventilated spaces.

Scope of delivery

• GX-D250 CO₂ warning device with pre-assembled sensor
• User manual
• Mounting accessories

Safety instructions – General

• Before installation or operation, read the user manual carefully.
• Installation must be carried out by qualified personnel.
• Packaging material is not a toy. Keep it away from children.

Intended use

• The GAS ALARM GX-D250 is a carbon dioxide warning device for residential and similarly used spaces, equipped with an external NDIR sensor.
• An LCD display continuously provides information on air quality assessment and shows the exact measured ppm value of the CO₂ concentration in the ambient air.
• The GX-D250 is designed to detect exhaled air and encourage proper ventilation when air quality deteriorates.
• The GX-D250 is not suitable for monitoring CO₂ from pressurized systems or dry ice processing.
• The device provides acoustic and optical alarms, while a potential-free relay can activate forced ventilation. A second relay triggers in case of technical faults detected by the device itself. The sensor, evaluation, and software were tested by TÜV Süd during development; safety and stability were confirmed for the system.
• The complete GX-D250 device itself has not been tested by TÜV.
• This fixed-installation unit must not be used in explosive atmospheres.
• Any use other than that described above is not permitted.