SOH-A2 de Hydrogen Sulfide Introduction Personal gas safety monitors can be found in almost every industry, with the requirement for multiple gas detection becoming commonplace. Sulfur gases are toxic with a complex chemistry. Measuring both SO2 and H2S provides the information for separating the corrosive gases, but with different toxicologies. Response time t9o (s) from zero to 10ppm SO2 < 15 Zero current ppm equivalent in zero air < ± 0.2 Resolution rms noise (ppm equivalent) < 0.2 Range ppm SO2 limit of performance warranty 20 Linearity ppm error at full scale, linear at zero and 10 ppm SO2 < ±2 Overgas limit ppm maximum SO2 for stable response to gas pulse 50 LIFETIME Zero drift ppm equivalent change/year in lab air < 0.5 Sensitivity drift % change/year in lab air, monthly test < 6 Operating life months until 80% original signal (24 month warranted) 24 CROSS SENSITIVITY Filter capacity ppm hours of Hydrogen Sulfide nd Cl2 sensitivity % measured gas @ 10ppm Cl2 < -50 CO sensitivity % measured gas @ 400ppm CO < 2 KEY SPECIFICATIONS Temperature range oC -30 to 50 Humidity range %rh continuous (see note below) 15 to 90 Storage period months @ 3 to 20oC (stored in sealed pot) 6 Load resistor Q (recommended) 10 to 47 Note: Above 85% rh and 40OC a maximum continuous exposure period of 10 days is warranted. Where such exposure occurs the sensor will recover normal electrolyte volumes, when allowed to rest at lower %rh and temperature levels for several days.

erformance Data Performance Data Sulfur Dioxide Channel Figure 1 SO2 Channel response to 20ppm SO2 Figure 1 shows the SOH-A2 fast response, stable output and return to baseline in 20ppm SO2. Figure 2 SO2 Channel Sensitivity Temperature Dependence 105 Figure 2 shows the % variation in sensitivity caused by changes in temperature. The data is taken from a typical batch of sensors. Figure 3 Channel Zero Temperature Dependence 0.6 Zero current, referenced to 20oC (equivalent ppm) Technical Specification Figure 3 shows the variation in zero output caused by changes in temperature, expressed as ppm...

SOH-A2 Specification contd , 020,2 Including Label All dimensions in millimetres (± 0.15mm) Bottom View Side View PERFORMANCE Sensitivity nA/ppm in 20ppm H2S 450 to 900 Response time t90 (s) from zero to 20ppm H2S @ 20oC < 25 Zero current ppm equivalent in zero air ± 0.25 Resolution rms noise (ppm equivalent) < 0.1 Range ppm H2S limit of performance warranty 100 Linearity ppm error at full scale, linear at zero and 20ppm H2S < ±5 Overgas limit maximum ppm H2S for stable response to gas pulse 200 LIFETIME Zero drift ppm equivalent change/year...

erformance Data Performance Data Hydrogen Sulfide Channel Figure 5 H2S Channel Response to 25ppm H2S Figure 1 shows the SOH-A2 fast response, stable output and return to baseline in 20ppm H2s. Figure 6 H2S Channel Sensitivity Temperature Dependence 105 Figure 6 shows the % variation in sensitivity caused by changes in temperature. The data is taken from a typical batch of sensors. Figure 7 H2S Channel Zero Temperature Dependence Zero current, referenced to 20oC (equivalent ppm) Technical Specification Figure 7 shows the variation in zero output caused by changes in temperature, expressed as ppm...