Makeblock Sensor "Gas Sensor V1" / Gas für MINT Roboter

Makeblock Sensor "Gas Sensor V1" / Gas for MINT Robot.

Me gas sensor contains MQ2 type smoke sensor, which has good repeatability, long-term stability, short response time and durable working performance. It is widely used as a gas leakage monitoring device in family and business, and is suitable for detecting liquefied natural gas (LNG), butane, propane, methane, alcohol, hydrogen, smoke and so on. Its black ID means it has an analog port and must be connected to the port with the black ID on the Makeblock Orion.

technical specifications

• Operating voltage: 5.0V ± 0.1 V
• Heating voltage: 5.0V ± 0.1 V
• Heating resistance: 33Ω ± 5% (at room temperature) ? Heating power: <800mw
• Warm-up time: >24h
• Detection range: 100-10000 ppm
• Operating temperature: 20 ± 2? (in standard condition)
• Operating temperature: -20?-50?
• Relative humidity: < 95%RH
• Oxygen concentration: 21% (in standard condition)
• Module dimensions: 51 x 24 x 18mm(L x W x H)

Functional characteristics:

• The white surface of this module is the reference surface for the contact area of the metal supports
• Adjustable resistor to set the sensitivity
• Preheat for a while before use to keep it warm after preheating
• Blue indicator lights up when a certain amount of combustible gas has accumulated and is detected.
• Provide output port for digital and analog signal
• Strong stability and fast detection
• Support mBlock GUI programming, and applicable for users of all ages
• Adopt RJ25 jack for easy connection
• Provide pin type port to support most development boards including Arduino series

Pin definitions:

The Me gas sensor connector has three pins, and their functions are as follows:

Connection

Connection with RJ25 Since the connector of the Me-Gas sensor has a black ID, you need to connect the connector with the black ID on the Makeblock Orion when you use the RJ25 connector. Using the Makeblock Orion as an example, you can connect ports #6, #7, and #8.

Connection with dupont wire If the dupont wire is used to connect the module to the Arduino UNO baseboard, its DO pin should be connected to the digital port

Principle

Me Gas Sensor has an adjustable resistor to adjust the sensitivity of the sensor to the smoke. The smoke concentration depends on the distance between the sensor and the smoke source. In the same environment, the closer the distance, the higher the smoke concentration; the farther the distance, the lower the smoke concentration. Therefore, it is necessary to set a voltage value that corresponds to the corresponding smoke concentration threshold.

Detection principle: MQ-2 type smoke sensor uses tin oxide as gas-sensitive semiconductor material, which acts as N-type ionic semiconductor on the surface. When the temperature is in the range of 200~300?, the tin oxide adsorbs the atmospheric oxygen and forms negative oxygen ions, so that the electron density of the semiconductor is decreased and its resistance is increased. When the potential energy barrier at the grain boundary is modulated by the smoke when in contact with smoke, its change causes the conductance to change. From this, one can obtain the information whether the smoke exists or not. The greater the smoke concentration, the greater the conductance and the lower the output resistance. The decrease of the mass resistance of the sensor leads to an increase of the output voltage to ground. By comparing the output voltage and the threshold voltage using the comparator on the module, the concentration of the detected smoke can be determined.