The SB-19 is a tin dioxidesemiconductor gas sensorwhich has an excellentsensitivity and selectivity tohydrogen. Significant lowpower consumption design(120mW) is advantageous forportable gas detectiondevices.

StructureGas sensitive semiconductormaterial is a mini bead type and aheater coil and electrode wire areembedded in the element. Thesensing element is installed in themetal housing which uses doublestainless steel mesh (100 mesh) inthe path of gas flow. The mesh is ananti-explosion feature (Fig 1).Operating conditions

Fig 2 shows the standard operatingcircuit for this model. The change ofthe sensor resistance (RS) is obtainedas the change of the output voltageacross the fixed or variable resistor(RL). In order to obtain the bestperformance and specifiedcharacteristics, the values of theheater voltage (VH) circuit voltage(VC) and load resistance (RL) must bewithin the range of values given inthe standard operating conditionsshown in the Specification table on

Sensitivity characteristicsFig 3 shows the sensitivitycharacteristics curves of the SB-19(typical data). Sensitivitycharacteristics of the FIS gas sensorsare expressed by the relationshipbetween the sensor resistance andgas concentration. The sensorresistance decreases with anincrease of gas concentration basedon a logarithmic function.The sensitivity characteristics ofthe SB-19 is specified by thefollowing parameters.

• Sensor resistance level: athydrogen 100 ppm

• Sensor resistance changeratio: between hydrogen100 ppm and 1000 ppm

See the specification table on thenext page for further details. The SB-19 is a tin dioxidesemiconductor gas sensor

which has an excellentsensitivity and selectivity tohydrogen. Significant lowpower consumption design(120mW) is advantageous forportable gas detectiondevices.StructureGas sensitive semiconductormaterial is a mini bead type and aheater coil and electrode wire areembedded in the element. Thesensing element is installed in themetal housing which uses doublestainless steel mesh (100 mesh) inthe path of gas flow. The mesh is ananti-explosion feature (Fig 1).Operating conditions

Fig 2 shows the standard operatingcircuit for this model. The change ofthe sensor resistance (RS) is obtained

as the change of the output voltageacross the fixed or variable resistor

(RL). In order to obtain the bestperformance and specifiedcharacteristics, the values of theheater voltage (VH) circuit voltage(VC) and load resistance (RL) must bewithin the range of values given inthe standard operating conditions