TGS 2620 - for the detection of Solvent Vapors Eeatures: Applications: * Low power consumption * Alcohol testers * High sensitivity to alcohol and organic * Organic vapor detectors/alarms solvent vapors * Solvent detectors for factories, dry cleaners, * Long life and low cost and semiconductor industries * Uses simple electrical circuit The sensing element is comprised of a metal oxide semiconductorlayer formed on an alumina substrate of a sensing chip together with an integrated heater. In the presence of a detectable gas, the sensors conductivity increases depending on the gas concentration inthe air. Asimple electrical circuit can convert the change in conductivity to an output signal which corresponds to the gas concentration. The TGS 2620 has high sensitivity to the vapors of organic solvents as well as other volatile vapors. It also has sensitivity to a variety of combustible gases such as carbon monoxide, making it a good general purpose sensor. Due to miniaturization of the sensing chip, TGS 2620 requires a heater current of only 42m. and the device is housed in a standard TO-5 package. The figure below represents typical temperature and humidity dependency characteristics. Again, the Y-axis is indicated as sensor resistance ratio (Rs!Ro), defined as follows: Rs = Sensor resistance in 300ppm of ethanal at various temperatures humidities Ro = Sensor resistances in 300pprm of ethanol at 20C and 65% R.H. 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 sansar resistance ratio (Rs/Ro) which is defined as follows: Rs = Sensor resistance in displayed gases at Various concentrations Ro= Sensor resistance in 300ppm of ethanal Sensitivity Ch wae, 7 Humidity D tency: 700 10 10 a = mT te cc 1 oo Gas: 300ppm Ethanol |s0-butane ogen Ethanol 0 a. 10 100 7000 10000 -20 -10 0 10 20 30 40 50 Gas concentration (ppm) Ambient temperature (C) IMPORTANT NOTE: OPERATING CONDITIONS IN WHICH FIGARO SENBO0RS ARE USED WILL WARY WITH EACH CUSTOMERS SPECIFIC APPLICATIONS. FIGARO STRONGLY RECOMMENDS CONSULTINGOUR TECHNICAL STAFF BEFORE DEPLOYING FIGARO.SENSORSINYOURAPPLICATIONAND, INPARTICLLAR, WHEN CUSTOMERS TARGET GASES ARE NOTLISTED HERE N. FIGARO CANNOT ASSUMEANY RESPONSI LLITY FOR.ANY USE OFITS SENSORS IN APRODUCT OF APPLICATION FOR WHICH SENSOR HAS MOT BEEN SPECIFICALLY TESTED EY FIGARO: 9 4 Ed a fe i ri ff & 5 2 Bl BW wk BB im Ul th #2 eB fF BZ sl Hhit: FEV PIED A B1006-1018 alte: 518033 Bih: O755-H5779118/83278609/832 78860 fH: 07655-83279284 fjiit: wow. apel lesz, cem Higa: Sensor@apeal losz. comBasic Measuring Circuit: The sensorrequires two voltage inputs: heater voltage (Vai and circuit voltage (Vel. The heater voltage (Vu) is applied to the integrated heater in order to maintain the sensing element at a specific temperature which is optimal for sensing. Circuit voltage (Vc) is applied to allow measurement of voltage (VRL) across a load resistor (RL) which is connected in series with the sensor. Acoammon power supply circuit can be used for both Ve and Vu to fulfill the sensor's electrical requirements. The value of the load resistor (Ri) should be chosen to optimize the alarm threshold value, keeping power consumption (Ps) of the semiconductor below a limit of 1amvV. Power consumption (Ps) will be highest when the value of Ris is equal to Rion exposure to gas. (+) e ; + - + bh aay a7 Model number TGS 2620 Sensing element type oA Standard package TOS metal can Target gases Alcohol, Solvent vapors Typical detection range 50 ~ 5,000 ppm Heater Voltage WH 5.0+0.2V DOVAG Standard circuit | circuit voltage | Ve | S.oto02vDC | Ps<15mw conditions Load resistance Ri Variable Ps = 15m\vV Heater resistance | Ry 82+ 802 at room temp. Heater current lH 42m Electrical characteristics | Heater power Pol 2tomw | vH=s.0vo0c under standard test | Consumption conditions Sensor resistance | Rs 1~5kQ in 300ppm ethanol Sensitivity ae Rs (200 ppm) (change ratio of Rs} 0.35 40.1 Rs (50pm) a: Ethanol vapor in air Test gas conditions at 2042C. GEtS%RH Standard test eee ee Ve = 5.0+0.01V Be conditions olay re Vu = 5.0+0.05V DC before test Conditioning period f days The value of power dissipation (Ps) can be calculated by utilizing the following formula: (Ve - Vay? Rs Ps = Sensor resistance (Rs) is calculated with a measured value of Vat by using the following formula: Wo -VEL y Ry VRL Rs = Side view ?7H20.5 10.0 +10 eh 00.55 20.05 Pin connection: 1 > Heater 2: Sensor electrode (-) 3: Sensar electrode (+) 4 Heater fe & Sw we) Bk BB im Wi th YZ 7 FBO 2 ol Hhik: Bev PIE AI 1006-1018 lta: 518033 Hid: OF55-85279118/832 79699832 78860 EH: 0756-83279284 faltit: www. apollosz. com Higa: Sensor@apoal losz. com