PRODUCT INFORMATION TGS 832-A00 - for the detection of Chlorofluorocarbons Features: Applications: * Portable and fixed installation refrigerant leak detectors * High sensitivity to refrigerant gases * Quick response * Long term stability * Uses simple electrical circuit The sensing element of Figaro gas sensors is a tin dioxide (SnO2) semiconductor which has low conductivity in clean air. 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 832-A00 has high sensitivity to refrigerant gases commonly used in air conditioning systems and refrigerators such as R-134a, R-404a, R-407c, and R-410. TGS832-A00 has a gas diffusion hole in the sensor cap as well as in the sensor base. By using the sensor with a suction pump, response speed can be accelerated, making it suitable for portable gas leakage checkers. 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 of displayed gases at various concentrations Ro = Sensor resistance at 100ppm of R-134a 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 at 100ppm of R-134a at various temperatures/humidities Ro = Sensor resistance at 100ppm of R-134a at 20C and 65% R.H. Sensitivity Characteristics: Temperature/Humidity Dependency: 10 Air R-407c Ethanol R-134a R-410a R-404a R-22 2.0 1.2 1 Rs/Ro 1.0 Rs/Ro 40% R.H. 65% R.H. 100% R.H. 0.5 0.1 10 100 Concentration (ppm) 1000 -10 0 10 20 30 40 50 60 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. Structure and Dimensions: 1 Sensing Element: SnO2 is sintered to form a thick film on the surface of an alumina ceramic tube which contains an internal heater. 2 Sensor Cap 3 Sensor Base: Nylon 66 4 Flame Arrestor: 100 mesh SUS316 double gauze 45 1 5 2 4 45 6.50.5 16.50.5 6 1.00.5 9.5 3 17 0.5 um : mm Pin Connection and Basic Measuring Circuit: The numbers shown around the sensor symbol in the circuit diagram at the right correspond with the pin numbers shown in the sensor's structure drawing (above). When the sensor is connected as shown in the basic circuit, output across the Load Resistor (VRL) increases as the sensor's resistance (Rs) decreases, depending on gas concentration. Basic Measuring Circuit: Standard Circuit Conditions: Item Symbol Rated Value Remarks Heater voltage VH 5.00.2V AC or DC Circuit volatge VC max. 24V DC only Ps15mW Load Resistance RL variable 0.45k min. Electrical Characteristics: Item Symbol Condition Specification Rs R-134a at 100ppm/air 4k ~ 40k Rs/Ro Rs (R-134a at 300ppm/air) Rs (R-134a at 100ppm/air) 0.50 ~ 0.65 Heater resistance RH Room temperature 30.0 3.0 Heater power consumption PH VH=5.0V 835mW (typical) Sensor resistance Change ratio of sensor resistance Standard Test Conditions: TGS 832 complies with the above electrical characteristics when the sensor is tested in standard conditions as specified below: Test Gas Conditions: 202C, 655%R.H. Circuit Conditions: VC = 10.00.1V (AC or DC), VH = 5.00.05V (AC or DC), RL = 10.0k1% Preheating period before testing: More than 7 days FIGARO ENGINEERING INC. 1-5-11 Senba-nishi Mino, Osaka 562-8505 JAPAN Phone: (81)-72-728-2561 Fax: (81)-72-728-0467 www.figaro.co.jp email: figaro@figaro.co.jp REV: 10/12 Sensor Resistance (Rs) is calculated by the following formula: Rs = ( VC -1) x RL VRL Power dissipation across sensor electrodes (Ps) is calculated by the following formula: Ps = VC2 x Rs (Rs + RL)2