PRODUCT INFORMATION TGS 3870-B00 - for the detection of both Methane and Carbon Monoxide * Miniature size and low power consumption * High sensitivity and selectivity to both methane and carbon monoxide (CO) * Low sensitivity to alcohol vapor * Long life and low cost * Combination methane and carbon monoxide detectors TGS 3870-B00 is a micro-bead type semiconductor gas sensor for the detection of both methane and carbon monoxide. Using a micro-bead gas sensing structure, both methane and carbon monoxide can be detected with a single sensor element by periodic application of two different heater voltages (high and low). Miniaturization of the gas sensing bead results in a heater power consumption of only 38mW (average). TGS 3870-B00 has low sensitivity to alcohol vapors (a typical interference gas in the residential environment) and has high durability, making the sensor ideal for consumer market gas alarms. The figure below represents typical sensitivity characteristics, all data having been gathered at standard test conditions (see reverse side of this sheet). The Y-axis is indicated as sensor resistance ratio (Rs/Ro) which is defined as follows: Rs = Sensor resistance in displayed gases at various concentrations Ro = Sensor resistance in 3000ppm of methane The figure below represents typical sensitivity characteristics, all data having been gathered at standard test conditions (see reverse side of this sheet). The Y-axis is indicated as sensor resistance ratio (Rs/Ro) which is defined as follows: Rs = Sensor resistance in displayed gases at various concentrations Ro = Sensor resistance in 100ppm of CO Sensitivity Characteristics (methane): IMPORTANT NOTE: OPERATING CONDITIONS IN WHICH FIGARO SENSORS ARE USED WILL VARY WITH EACH CUSTOMER’S SPECIFIC APPLICATIONS. FIGARO STRONGLY RECOMMENDS CONSULTING OUR TECHNICAL STAFF BEFORE DEPLOYING FIGARO SENSORS IN YOUR APPLICATION AND, IN PARTICULAR, WHEN CUSTOMER’S TARGET GASES ARE NOT LISTED HEREIN. FIGARO CANNOT ASSUME ANY RESPONSIBILITY FOR ANY USE OF ITS SENSORS IN A PRODUCT OR APPLICATION FOR WHICH SENSOR HAS NOT BEEN SPECIFICALLY TESTED BY FIGARO

Basic Measuring Circuit: The sensor requires two voltage inputs: heater voltage (Vh) and circuit voltage (Vc). The sensor has three pins: Pin #3--heater (+), Pin #2--sensor electrode (+), and Pin #1--common (-). To maintain the sensing element at specific temperatures which are optimal for sensing two different gases, heater voltages of 0.9V and 0.2V are alternately applied between pins #1 and #3 during a 20 second heating cycle. Circuit voltage (Vc) is applied between both ends of the sensor (Rs) and a load resistor (Rl), which are connected in series, to allow measurement of voltage (Vrs)....