GF-201-CO2 Gas Sensor

Overview

The GF-201-CO2 is a fixed-point carbon dioxide gas detector for continuous monitoring in greenhouses, produce storage, and other enclosed agricultural spaces. A sensing cell with automatic temperature compensation and zero/span drift correction holds readings stable over long deployments, while a flameproof aluminium alloy enclosure (Ex d IIC T6) suits demanding installations where the detector must run unattended.

The detector shows live concentration and alarm status on its LCD and drives three independent output paths at once: a 4-20 mA analog loop, an RS485 Modbus-RTU bus, and two normally-open alarm relays. That lets a single unit report to an Omni Genesis controller while its relays directly trigger a fan, damper, or local horn.

This detector measures gas-phase CO2 in air. For dissolved CO2 in aquaculture water, see the CO2-100 dissolved CO2 sensor.

Why Monitor CO2

In greenhouses, CO2 enrichment only pays off if the concentration at the crop actually reaches the target. A fixed detector closes the loop on the dosing system: it verifies the enrichment level in real time, catches failed or leaking dosing lines, and shows how fast levels fall when vents open.

In enclosed produce storage, fermentation rooms, and ripening rooms, the hazard runs the other way. Respiring produce and active fermentation release CO2 continuously, and in a sealed room it accumulates to levels that endanger anyone who walks in. Continuous fixed-point detection gives an early, audible warning, and the two relays can drive the ventilation directly so the room clears itself before staff enter.

Key Features

• Dedicated CO2 range: 0-5000 ppm with 1 ppm resolution; 0-1000 ppm, 0-2000 ppm, and 0-20 %VOL ranges available on request
• Fast response: ≤15 s (T90), with automatic temperature compensation and zero/span drift correction
• Two-stage alarm: independent low and high relays, freely configurable set points
• Three outputs in parallel: 4-20 mA, RS485 Modbus-RTU, and two dry-contact relays
• Hazardous-area rated: flameproof Ex d IIC T6 aluminium enclosure, IP65
• Wide supply: 12-30 VDC, ≤2 W
• Field serviceable: LCD menu for calibration, alarm set points, and bus address

How It Works

The sensing cell, with automatic temperature compensation, produces a signal proportional to the CO2 concentration at the detector inlet. On-board electronics linearise that signal, display it in ppm, and publish it on the analog and digital outputs. When concentration crosses a configured set point, the matching relay changes state to drive an alarm or ventilation interlock.

Installation

Because CO2 is heavier than air, mount the detector low, roughly 0.3-0.6 m above floor level, near likely accumulation zones in storage and fermentation rooms. In greenhouses used for enrichment verification, mount at canopy height instead, where the concentration the crop sees is what matters. Keep the sensor inlet clear of splashing water, oil, and dust, and leave service access around the housing. Calibrate with certified gas at commissioning and at least every six months thereafter.

One Detector, Replaceable Sensing Cell

The GF-201 family shares one platform: the same flameproof housing, display, relays, and outputs, with a replaceable sensing cell that sets the target gas. The family: H2S, NH3, CO2, O2, and CH4.

Additional sensing cells are available for the same platform by quote:

Gas	Formula	Selectable ranges
Carbon monoxide	CO	0-500 to 0-10000 ppm
Ozone	O3	0-10 to 0-1000 ppm
Chlorine dioxide	ClO2	0-20 to 0-1000 ppm
Chlorine	Cl2	0-10 to 0-200 ppm
Sulfur dioxide	SO2	0-100 to 0-1000 ppm
Nitrogen dioxide	NO2	0-100 to 0-1000 ppm
Formaldehyde	CH2O	0-5 to 0-200 ppm
Ethylene	C2H4	0-50 to 0-1000 ppm

Contact us with your target gas and range for a tailored quote.

Connectivity and Integration

The RS485 Modbus-RTU output (9600 bps, 8-N-1) connects directly to the Omni Genesis and Genesis Lite controllers and to any PLC or DCS that speaks Modbus. The parallel 4-20 mA loop covers legacy analog inputs, and the two relay contacts provide a wiring-free local trip for fans and ventilation. This is the same modular approach as the rest of the Agrinovo range: one controller, any mix of sensors.