RKI Direct Connect Gas Sensor (O2, H2S, CO)

The RKI Direct Connect sensors for O2, H2S, and CO provide reliable, economical electrochemical detection of the most common toxic and asphyxiation hazards. Designed for RKI Beacon controllers, sensors mount directly to the controller box or in remote explosion-proof junction boxes. All three gas types carry explosion-proof construction with flame arrestors, approved for Class I, Groups B, C, and D hazardous areas.

Compatible with Beacon 110, Beacon 200, and Beacon 410 controllers. Also see the LEL, CH4, and CO2 sensor and the H2-specific LEL sensor.

Key Features:

• Electrochemical plug-in sensor design — no tools required for replacement
• Fast response time
• Compatible with Beacon 110, Beacon 200, and Beacon 410
• Long sensor life
• Indoor/outdoor rated
• Water-repellent patented sensor coating (except toxics)
• Explosion-proof construction

Oxygen (O2)

Measuring Range: 0–25%

Lower Detectable Limit (LDL): 0.1% volume

Response Time: 90 seconds

Life Expectancy: 2–3 years with normal service

Part Numbers:
65-2514RK — Sensor only
65-2515RK — With J-Box

Hydrogen Sulfide (H2S)

Measuring Range: 0–100 ppm

Lower Detectable Limit (LDL): 2% of full scale

Response Time: 60 seconds

Life Expectancy: 2–3 years with normal service

Part Numbers:
65-2428 — Sensor only
65-2427RK-05 — With J-Box

Carbon Monoxide (CO)

Measuring Range: 0–300 ppm

Lower Detectable Limit (LDL): 2% of full scale

Response Time: 90 seconds

Life Expectancy: 2–3 years with normal service

Part Numbers:
65-2438 — Sensor only
65-2437RK-05 — With J-Box

PK Safety services RKI Instruments fixed gas detection systems in-house — call 800.829.9580 for product guidance or service scheduling.

Related Searches
Fixed Gas Detectors, Gas Detection, RKI Instruments, Safety Equipment, Sensors

Frequently Asked Questions

What gases do these Direct Connect sensors monitor?

This product page covers three sensors: Oxygen (O2, 0–25%), Hydrogen Sulfide (H2S, 0–100 ppm), and Carbon Monoxide (CO, 0–300 ppm). Each is an electrochemical plug-in sensor ordered separately by part number.

Are these sensors explosion-proof?

Yes. The O2, H2S, and CO Direct Connect sensors carry explosion-proof ratings with flame arrestors for use in NEC Class I, Groups B, C, and D hazardous locations. Always verify the specific area classification and certificate details before installation.

What are the OSHA permissible exposure limits for H2S and CO?

Under 29 CFR 1910.1000, OSHA's PEL for H2S is 20 ppm (ceiling) with a 50 ppm 10-minute peak allowance. For CO, the OSHA PEL is 50 ppm as an 8-hour TWA. Fixed monitoring supports compliance verification — consult an industrial hygienist to set appropriate alarm thresholds for your application.

Can I mount the sensor away from the controller?

Yes. Direct Connect sensors are designed to mount either directly on the Beacon controller enclosure or in remote explosion-proof junction boxes, enabling detection at points far from the controller panel. Mounting in a J-Box requires the J-Box part number variant (e.g., 65-2515RK for O2).

How often should electrochemical sensors be replaced?

Typical life expectancy for O2, H2S, and CO electrochemical sensors is 2–3 years under normal service conditions. Exposure to high gas concentrations, extreme temperatures, or sensor-poisoning compounds can shorten this. Regular bump testing and calibration help confirm sensor health between scheduled replacements.

How does PK Safety support RKI fixed detection systems?

PK Safety services RKI Instruments fixed gas detection equipment in-house with factory-trained technicians — including sensor replacement, calibration, and controller diagnostics. Call 800.829.9580 to discuss service options.