M-Series Detector Head

The RKI low cost CO/H2S transmitter is a highly reliable and very cost effective basic 4-20 mA transmitter for the detection of carbon monoxide and hydrogen sulfide. The electronics are protected inside a plastic enclosure to avoid damage from mechanical abuse, water, dust or corrosion. Sensors for H2S and CO are long life and typically last 2 - 3 years.

The transmitter operates from 24 VDC (11VDC to 30 VDC), and provides a 4-20 mA signal which can be connected to a wide variety of controllers. The low cost CO/H2S can be used either indoors or in semi-enclosed areas.

The only tools required to calibrate the low cost CO/H2S transmitter are a voltmeter, screwdriver, and calibration gas. The zero and calibration functions are performed by adjusting potentiometers on the amplifier board. The amplifier board has test jacks for the connection of a voltmeter for calibration purposes, and the sensor response is viewed on the voltmeter as a 100mV to 500mV signal. Field calibration can be performed easily and quickly by one person.

Part #	H2S 65-2424RK	CO 65-2434RK
Min Operating Voltage	11 VDC
Max Operating Voltage	30 VDC
Max Current Draw	25 mA (2 wire system)
Signal Output	4 mA at 0 ppm H2S 20 mA at 100 ppm H2S	4 mA at 0 ppm CO 20 mA at 300 ppm CO
Response Time	20 seconds to 90% of concentration	45 seconds to 90% of concentration
Operating Environment
Location	Indoors or semi-enclosed areas
Temperature	0 to 120° F
Humidity	0 - 99% RH, non condensing
Housing	Plastic, water / dust resistant enclosure 2.5" W x 4.0" H x 1.5" D
Sensor
Type	Electrochemical
Life Expectancy	2 years normal service when intermittently exposed to H2S	2 to 3 years normal service
Controls
Zero	Sets transmitter output to 4 mA with zero output from H2S sensor	Sets transmitter output to 4 mA with zero output from CO sensor
Span	Sets transmitter output to 20 mA with 100 ppm output from H2S sensor	Sets transmitter output to 20 mA with 300 ppm output from CO
Tools Needed	Screwdriver and voltmeter used to make adjustments