The SMT-027 is a semiconductor type gas sensor used to detect ammonia in the environment. When the sensor encounters the gas to be detected, the conductivity of the sensor changes with the concentration of the target gas. Using a simple test circuit, this change in conductivity is converted into an electronic signal output corresponding to the change in gas concentration. The sensor is small in size and encapsulated in a 4-pin metal shell. It is a low-cost sensor suitable for a variety of applications.
● High sensitivity
● Fast response and recovery time
● Long life
● Low cost
● The test circuit is simple
● Civilian ammonia alarm
● Portable ammonia alarm
● Industrial ammonia alarm
| Item | Parameter |
| Detection Gas | Ammonia |
| Detection Concentration Range | 5～500ppm (ammonia) |
| Heating Voltage(VH) | 5V±0.1V DC or PWM |
| Sensor Voltage | ≤24V DC |
| Heating Element Resistance (RH) | 65Ω±10Ω (room temperature) |
| Heating Power (PH) | 280mW±25mW |
| Sensitivity | Rs(in air)/Rs(50ppm NH 3 )≥ 2 |
| Output Voltage (V S ) | ≥0.5V (in 50ppm NH 3 ) |
| Concentration Response Ratio | ≤0.6(R200ppm/R50ppm NH 3 ) |
| Test Environment | 20℃±2℃; 55%±5%RH |
| Life Time | 5 years |
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