The CO Guardian 353P-201 is a remote-mounted carbon monoxide (CO) detector specifically engineered for experimental and homebuilt aircraft. Its compact, lightweight design allows it to be installed in a small space behind the instrument panel, making it ideal for aircraft with limited panel real estate. The unit provides precise CO monitoring for both the cockpit and cabin, includes built-in cabin pressure altitude alerts, and supports external display integration through compatible avionics systems (see approved hardware list).
The high-sensitivity onboard CO sensor continuously monitors carbon monoxide levels and activates alerts when concentrations exceed 50 parts per million (PPM). When CO levels reach 50–99 PPM for a duration of 3–5 minutes, the system triggers an 85 dB audible alarm and flashes an externally mounted amber warning light. If CO levels exceed 99 PPM, an audible alert and flashing red warning light activate immediately.
An integrated pressure sensor provides altitude-based reminders at 10,000 feet, 12,500 feet, and 14,000 feet, prompting the pilot to use supplemental oxygen. These altitude alerts are displayed through an optional annunciator light.
The 353P-201 features an RS-232 serial interface, allowing real-time CO level data and alerts to be displayed on a wide range of compatible PFDs, MFDs, and engine monitoring systems. Refer to the approved product list for supported displays.
Measuring just 2.25 inches by 1.5 inches and weighing only 3.5 ounces, the CO Guardian 353P-201 mounts easily in a remote location using the included bracket. Installation typically takes 2–4 hours. The system requires an external annunciator light (sold separately) for primary CO warnings, as well as a panel-mounted test/reset momentary switch to ensure proper operation and safety.
