MQ-135 NH3 Amonia Benzene Alcohol Gas Sensor ADC121C 12-Bit ADC I²C Mini Module

The MQ-135 Gas sensor makes it easy to monitor ammonia, benzene, or alcohol air concentration levels using our I2C Mini Module form factor. The MQ135 is connected to an ADC121C 12-Bit Analog to Digital converter, which is capable expanding to 9 gas sensors per I2C port using just two address jumpers (making full use of the floating address system).

The MQ-135 is capable of sensing ammonia (10ppm-300ppm), benzene (10ppm-1,000ppm), and alcohol (10ppm-300ppm) air concentration levels. The ideal sensing condition for the MQ135 is 20°C ±2°C at 65% ±5% humidity. An internal preheater inside the sensor helps achieve the ideal sensing conditions, but the datasheet recommends over 24 hours for preheating to achieve optimal accuracy. Because of the internal preheater, this sensor requires more current than most of our I2C Mini Modules. We measured 139ma for this I2C Mini Module so we strongly recommend planning a power strategy for your I2C master device to deliver no-less than 150ma per sensor! This sensor comes pre-calibrated to the datasheet’s recommended values; however, final calibration may be required for accurate measurements, as we do not stock the equipment for full-scale calibration of these sensors.

All I2C Mini Modules are designed to operate at 5VDC. Using a convenient 4-Pin plug, devices can be daisy chained onto the I2C Bus, eliminating the need for soldering. Simply plug together the devices you need for your next automation application. Pull-up resistors are included with all NCD master devices. If you are wiring in your own I2C port, on-board 4.7K jumper-selectable pull-up resistors are available for convenience purposes.

What is the NCD I2C Interface?

NCD is the creator of plug and play modular hardware using the NCD I2C Interface connector standard.  NCD I2C devices allow you to chain together several devices on the I2C bus, and communicate to each device individually at high speed (subject to the limitations of I2C).  The NCD I2C Interface uses a standard 4-Pin I2C Input and I2C Output connector.  NCD I2C devices communicate 5V I2C data and provides 5V DC power through this connector.  NCD I2C devices use standard I2C communications for all data transport, which is supported by nearly every microcontroller in production today.  The NCD I2C Interface is strictly a 5V standard, which is ideal for transport across longer cables.  NCD I2C devices always include a 6″ (152mm) 4-conductor I2C cable.  NCD I2C Mini Modules always include a 3″ (76mm) 4-conductor I2C cable.  Cables and connectors are available separately for designers who would like to include their own NCD I2C Interface into their designs.

Plug and Play Connectivity

NCD I2C devices will plug in to any available NCD I2C Output.  This includes just about everything we make in the NCD IoT Category, including all NCD IoT devices.  We also manufacture a wide range of I2C adapters that make it easy to plug NCD I2C Devices directly into most computing platforms.  The NCD I2C Interface adapters are available for Arduino, Banana Pi, BeagleBone, Bluz, C.H.I.P., ESP8266, Onion Omega, Particle Photon and Electron, PyCom, Raspberry Pi, 2, 3, and Zero, and Windows.  We are always working to add new platform support for NCD I2C devices.  NCD I2C Interface devices are compatible with just about everything in the microcontroller industry.

Unlimited I2C Expansion

Based on our plug-and-play I2C interface standard, all NCD I2C devices are equipped with a I2C output port, making it easy to expand to a wide variety of sensors, current monitors, relay controllers, PWM controllers, and much more!  We are always designing new expansions for our modular plug-and-play I2C framework.  We are dedicated to building a product line of interconnected devices to simplify all forms of automation.  Re-use or upgrade your hardware in seconds by selecting the modules that best fit your needs, and chaining them together using the included I2C expansion cables!

Powering NCD I2C Interface Devices

Some NCD I2C devices require a external power supply, others may be powered through the 4-Pin I2C bus connector at 5VDC, and other devices are jumper selectable between external and I2C bus power.  All I2C mini modules are powered through the 5V I2C bus connector, greatly simplifying connectivity.

Features

• I2C Ammonia Benzene Alcohol Gas Sensor
• Sensitivity range between 10ppm and 1,000ppm
• 100KHz to 3.4MHz Communication Speed
• I2C Mini Module Form Factor
• Windows AnyI2C GUI Software
• Cloud Plug Compatible
• Modular MQ135 Breakout Board