RKI M2A Explosion Proof Gas Detector Heads

The RKI M2A™ is a state-of-the-art transmitter that can operate as an independent, stand-alone monitor or as part of an integrated system. The M2A connects with an analog or digital signal to virtually any controller, PLC, or DCS. Setup procedures are simplified with user friendly push buttons and OLED menus. It utilizes a magnetic wand technique for performing non-intrusive calibration. The M2A provides an automatic zero drift correction feature, which results in more stable readings and reduces the need for adjustments due to sensor aging.

The housing of the M2A does not need to be opened for zeroing or calibration, making it unnecessary to declassify the area for routine maintenance. It is designed so that a complete field calibration can be performed by one person. Sensor construction is rated Class I, Div. 1 Groups B, C, D for flammables, CO, H2S, O2, and CO2, and Class I, Div. 2 for all other toxics.

The transmitter provides a 4-20 mA output in addition to a Modbus digital output. It also has two levels of alarms with relays, plus a fail alarm with relay. A digital display of the gas concentration, as well as alarm and status lights, can be viewed through the front window.

The toxic sensors are electrochemical type plug-in sensors, which provide high specificity, fast response, and long life. The plug-in design allows quick replacement in the field with no tools required. Toxic sensors are designed for use in Class I, Div. 2 hazardous locations. Sensors available for NH3, AsH3, Cl2, ClO2, HCN, PH3, and SO2

The M2A represents the latest leading edge technology in sensor / transmitters today.

— Operates with or without a controller

— Direct digital readout with OLED  cold temperature display

— Available gases include   ◦ LEL, O2, H2S, CO, CO2, and 100% Vol CH4  

— Infrared sensor for combustibles and CO2

— 4-20 mA & digital Modbus outputs standard

— 2 fully programmable alarm relays & fail relay

— Non-intrusive calibration via magnetic wand

— Explosion proof construction

— Patented water repellent sensor cover

— User friendly setup, push buttons & OLED menus

— Long-life sensors (2 + years typical)

Sensors

Catalytic

Lower Detectable Limit (LDL) 2% of full scale

Max Current Draw (24VDC): 160 mA with alarm 1 and 2 active and all relays energized

Response Time: 35 seconds or less

Life Expectancy: 2-3 year with normal service

Accuracy: +/- 5% of reading or +/- 2% of full scale. Which ever is greater

Sensor and Range Options: 0 - 100% LEL, 1% LEL Resolution, 0 - 9000 ppm CH4, 20 ppm Resolution, H2 Specific 0 - 100% LEL, 1% LEL Resolution

Galvanic Cell

Lower Detectable Limit (LDL) 0.1% Vol

Max Current Draw (24VDC): 125 mA with alarm 1 and 2 active and all relays energized

Response Time: 90 seconds or less

Life Expectancy: 2-3 year with normal service

Accuracy: +/- 0.5% Vol

Sensor and Range Options: O2 0 - 25.0% VOL, 0.1% Vol Resolution

Electrochemical

Lower Detectable Limit (LDL) 2% of full scale

Max Current Draw (24VDC): 125 mA with alarm 1 and 2 active and all relays energized

Response Time: 60 seconds or less for H2S, 90 seconds or less for CO

Life Expectancy: 2-3 year with normal service

Accuracy: +/- 5% of reading or +/- 2 ppm for H2S, +/- 5%of reading or +/- 5 ppm for CO. Which ever is greater.

Sensor and Range Options: H2S 0 - 100 ppm, 1 ppm Resolution, CO 0 - 300 ppm, 1 ppm Resolution

Infrared, LDL

Lower Detectable Limit (LDL) 2% of full scale

Max Current Draw (24VDC): 160 mA with alarm 1 and 2 active and all relays energized

Response Time: 30 seconds or less

Life Expectancy: 5 years + with normal service

Accuracy: +/- 5% of reading or +/- 2% of full scale. Which ever is greater

Sensor and Range Options: CH4 0 - 100% LEL, 1% LEL Resolution or 0-100% VOL, 1% Vol Resolution, HC (Hydrocarbons) 0 - 100% LEL, 1% LEL Resolution, CO2 0 - 5000 ppm, 20 ppm Resolution or 0 - 5% Vol, 0.1% Vol REsolution or 0 - 100% Vol, 1% Vol Resolution

Weather Resistant Patented water repellent sensor coating for all models.

Alarms

Alarm Settings Two fully programmable alarm set points, increasing / decreasing, latching /  self-resetting, on delays, off delays, normally energized or de-energized

Alarm Indication Visual LEDs. Alarm 1, Amber; Alarm 2, Red; Fail, Red

Relays 5 amp form ‘C’ contacts for alarm 1, alarm 2, and fail

Physical

Dimensions Height: 8.5” (215 mm), Width: 5.2” (132 mm), Depth: 4.5” (114 mm)

Display Alphanumeric OLED display. 8 characters per line;  2 lines for gas concentration readout, plus user-friendly calibration and setup

Enclosure Explosion proof for Class I, Div 1, Groups B, C, D.

Enclosure Rating NEMA 4X, explosion proof, watertight, cast aluminum with o-ring seal and epoxy powder coating

Controls Magnet used for calibration functions. Calibrates without opening the housing.  Internal push-button controls also available for calibration and setup

Operating Environment

Operating Temperature -40°F to 167°F -40°C to 75°C for Catalytic Sensors, -4°F to 113°F -20°C to 45°C for Galvanic O2 Sensor. -40°F to 104°F -40°C to 40°C for H2S sensor. 23°F to 104°F -5°C to 40°C for CO Sensor. -40°F to 122°F -40°C to 50°C for Infrared Sensors. 

Relative Humidity 5 - 95% RH non-condensing

Location Indoor or outdoor. Explosion proof for Class I, Div. 1, Groups B, C, D.

Operating Voltage 10 VDC - 30 VDC

Outputs

Analog Linear 4-20 mA signal, into 1000 ohms impedance max (24DC), 0 - 500 ohms max (12VDC) corresponding to 0 - full scale

Digital Modbus RTU output standard, fully configurable, 2-wire RS-485, 1200 to 19.2k baud

Controllers Beacon 110, Beacon 200, Beacon 410A, Beacon 800 as well as most DCS / PLC systems

Warranty One year material and workmanship