Saiya Sensor SY-VOC-35BPMA

The SY-VOC-35BPMA gas sensor consists of three main components: a MEMS silicon-based heater, nanomaterials, and an SMT ceramic housing. It is a gas sensor designed to detect VOC concentration. This sensor features high sensitivity, minimal susceptibility to temperature and humidity variations, and excellent stability. When the sensor operates stably in clean air, the sensitive resistance at that point is defined as the baseline resistance (R0). Once the target gas is present in the air, the conductivity of the semiconductor material changes, causing a corresponding change in the sensor's sensitive resistance (Rs). The concentration of the target gas is then calculated by mapping the ratio of the sensitive resistance (Rs) to the baseline resistance (R0). The basic detection circuit consists of a heater voltage (Vh), a circuit measurement voltage (Vc), and a load matching resistor (Rm). The heater voltage (Vh) is used to activate and maintain the sensitivity of the nanomaterials, while the circuit measurement voltage (Vc), in combination with the load matching resistor (Rm), is used to measure the load matching voltage (Vm). The sensor's sensitive resistance (Rs) can be calculated from the measured value of the load matching voltage (Vm) using the formula: Rs = (Vc/Vm - 1) × Rm. A constant voltage of 1.5V (Vh) is applied continuously to the heater pins Pin1 and Pin3, while a measurement voltage (Vc) with a period of 1.1s is applied to Pin2 and Pin4. During each Vc application cycle, the voltage is 3.3V for the first 0.1s, followed by no voltage for the remaining 1s. The sensor output is measured during the 0.1s pulse voltage application period.