PRODUCT INFORMATION TGS 2620 - for the detection of Solvent Vapors Features: Applications: * Low power consumption * High sensitivity to alcohol and organic solvent vapors * Long life and low cost * Uses simple electrical circuit * Alcohol testers * Organic vapor detectors/alarms * Solvent detectors for factories, dry cleaners, and semiconductor industries The sensing element is comprised of a metal oxide semiconductor layer formed on an alumina substrate of a sensing chip together with an integrated heater. In the presence of a detectable gas, the sensor's conductivity increases depending on the gas concentration in the air. A simple 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 42mA and the device is housed in a standard TO-5 package. 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 300ppm of ethanol 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 ethanol at various temperatures/humidities Ro = Sensor resistance in 300ppm of ethanol at 20C and 65% R.H. Sensitivity Characteristics: Temperature/Humidity Dependency: 10 100 35% 50% 65% 96% RH%: Air 10 Rs/Ro Methane Rs/Ro 1 1 CO Iso-butane Hydrogen 0 Ethanol 10 100 1000 Gas concentration (ppm) 10000 Gas: 300ppm Ethanol 0.1 -20 -10 0 10 20 30 40 50 Ambient temperature (C) 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 heater voltage (VH) 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. A common power supply circuit can be used for both VC and VH to fulfill the sensor's electrical requirements. The value of the load resistor (RL) should be chosen to optimize the alarm threshold value, keeping power consumption (PS) of the semiconductor below a limit of 15mW. Power consumption (PS) will be highest when the value of Rs is equal to RL on exposure to gas. Specifications: Structure and Dimensions: Model number TGS 2620-C00 Sensing element type D1 Standard package TO-5 metal can Target gases Alcohol, Solvent vapors Typical detection range 50 ~ 5,000 ppm Standard circuit conditions Electrical characteristics under standard test conditions Heater Voltage VH Circuit voltage VC 5.00.2V DC/AC Ps 15mW Load resistance RL Variable 0.45k min. Heater resistance RH 83 at room temp. (typical) Heater current IH 4 2 4m A Heater power consumption PH approx. 210mW Sensor resistance Rs 1 ~ 5 k in 300ppm ethanol Sensitivity (change ratio of Rs) Test gas conditions Standard test conditions 0.3 ~ 0.5 The value of power dissipation (PS) can be calculated by utilizing the following formula: (VC - VRL)2 RS Ethanol vapor in air at 202C, 655%RH 7 days Sensor resistance (Rs) is calculated with a measured value of VRL by using the following formula: RS = VC - VRL x RL VRL For information on warranty, please refer to Standard Terms and Conditions of Sale of Figaro USA Inc. REV: 01/05 Sensing element 7.80.5 Side view 10.01.0 o0.550.05 3.60.1 Rs (300ppm) Rs (50ppm) VC = 5.00.01V DC VH = 5.00.05V DC Circuit conditions o9.20.2 o8.10.2 5.00.2V DC/AC Conditioning period before test PS = Top view Bottom view 90 4 3 1 2 3.60.1 o5.1 u/m: mm Pin connection: 1: Heater 2: Sensor electrode (-) 3: Sensor electrode (+) 4: Heater FIGARO USA, INC. 121 S. Wilke Rd. Suite 300 Arlington Heights, Illinois 60005 Phone: (847)-832-1701 Fax: (847)-832-1705 email: figarousa@figarosensor.com