MQ137 NH3 Ammonia Gas Sensor Module for Arduino, ESP32, and Raspberry Pi | Shektronix
Rated 4.82 out of 5 based on 1582 customer ratings
$ 13.68
Expedited shipping
EU, UK and US scooter orders will be shipped expedited and free, often take 2-7 days to your door.
All spare parts and accessories will be shipped from China with shipping fees.
We typically dispatch orders between Mon-Friday. Orders often get dispatched within 24 hours after payment cleared. Weekend orders will be dispatched next Monday. Meanwhile, a shipping tracking number will be updated.
Destinations
Shipping Methods
Estimate Delivery Time
Costs
UK
DHL/Yodel/UPS/DX
2-3 Days
Free
EU
DPD/DHL
2-7 Days
Free
US
FedEx/UPS
2-7 Days
Free
Other destinations
EMS/DHL/FedEx
10-25 Days
contact us
Please note: Affected by Covid-19, there will be some delay on the delivery.
Products purchased through an authorized retailer must follow the return policies of the retailer and cannot be returned to norell directly. Products purchased through our website are subject to the terms and conditions below:
RETURNS If the return is caused by the consumer, consumer should be responsible for the shipping fee. The specific fee should be based on the express company you choose.
If due to our reasons, the goods received are damaged or not correct, and the consumer is not required to bear the shipping fee for this reason.
Returning products within 30 Days of delivery: Any product purchased can be returned within 30 days for a refund to the original method of payment. The customer will be responsible for return shipping costs. norell DOES NOT PROVIDE RETURN SHIPPING LABELS FOR BUYERS Remorse.
If an item arrives defective, norell will exchange it for a working product and provide a return shipping label for the defective product at no cost to the customer.
If return products show abnormal wear & tear or physical damage. We will deduct 30%-70% of the refund amount based on wear & tear or physical damage. This also includes missing parts or accessories sold with the product.
Follow these steps to return products within 30 days of delivery:
Start a return request on the live chat application.
click the bot icon to start.
choose “start a return” option.
provide details of the return.
our agent will contact you to confirm/arrange the return.
Pack the product in original packaging or sturdy box to ensure the product will be returned without damage. For original packaging, this must include the styrofoam inserts.
Once we receive and inspect the product, we will process the refund within 2 to 3 business days.
NOTICE: It is the buyer’s responsibility to keep the original packaging of the goods, and norell will be exempt from responsibility for return disputes caused by lack of packaging boxes.
NOTICE: We will not accept shipping damage claims filed more than 7 days after receipt of any products.
NOTICE: We will not accept fail delivery/missing package claims filed more than 7 days after receipt date of shipping tracking.
CANCELLATIONS
Items returned while in transit: If you wish to cancel your order after it has already been processed, please contact us to let us know.
In some situations, the product may end up being delivered after the cancellation request. If that is the case, it is the buyer’s responsibility to ship and return the product back to our warehouse.
If the customer service staff does not process your order cancellation request in time due to the time difference, and the order is finally sent out and cannot be intercepted, you will need to refuse delivery. If your rejection fails, you will pay the shipping fee for the return.
Our working hours are Hong Kong time: 9:00-18:00 Mon. – Fri.
Tracking your package
Using the tracking number provided in your order confirmation email you can check the status of your delivery with the carrier. Please see our shipping restrictions below for more information.
Shipping restrictions norell.fr will not accept product or product part orders being shipped to Canada, Puerto Rico, Hawaii or Alaska.
P.O. boxes norell can not ship to a U.S. Postal Service post office box. Please provide an actual street address.
APO/FPO addresses norell cannot ship to APO/FPO addresses.
Commercial mail boxes norell cannot ship to a commercial mailbox similar to a Mail Boxes Etc®. Please provide an actual street address.
Undeliverable packages When the carrier returns these undeliverable packages to us we issue a full refund excluding shipping charges. Please allow 30 days for refund to your credit card account.
These undeliverable packages will not be reshipped. A new order must be placed for the item. Please review our address accuracy tips above before placing another order.
The decision to label a shipment as undeliverable is made by the carrier usually for one of the following reasons:
Incorrect address If an address is incorrect or incomplete the package will be returned by the carrier. Please be careful when entering your address and proof read it for any mistakes before submitting your order. Customers are responsible for entering the correct shipping address.
Refused by recipient If you are placing an order to send as a gift it may be refused by a recipient who is not expecting to receive a gift. You may want to let the recipient know that they should be expecting a surprise.
Return address: Craig Hook Hookies Scooters 18 Park Parade Havant, Hampshire PO9 5AD UK
Category:
Description
The MQ137 NH3 Sensor is a high-performance ammonia gas detection module ideal for use with Arduino, ESP8266, ESP32, and Raspberry Pi. It uses the MQ137 gas sensor to detect ammonia (NH₃) concentrations in the environment. The module provides both analog and digital output signals, allowing flexible integration in IoT, automation, and air quality monitoring systems. This sensor works based on the change in resistance of the SnO₂ (tin dioxide) layer when exposed to ammonia gas. When ammonia is present, the sensor’s resistance changes, allowing the system to measure the gas concentration accurately. Key Features of MQ137 NH3 Sensor Sensitive to Ammonia (NH₃) Gas: Detects NH₃ concentrations from 5 ppm to 500 ppm. Dual Output: Provides both analog (AO) and digital (DO) signals for flexible use. Adjustable Sensitivity: Onboard potentiometer allows sensitivity tuning. Fast Response and Recovery: Detects ammonia presence within seconds. Easy Interface: Compatible with Arduino, ESP32, NodeMCU, and Raspberry Pi. Long Life and Stable Performance: Designed for reliable, long-term use. Wide Operating Voltage: Works on 5V DC supply. Onboard Signal Indicator LED: Indicates detection and power status. Compact Design: Perfect for integration in air monitoring and safety systems. Low-Cost and Easy to Use: Ideal for beginners and professionals in IoT projects. Technical Specifications Parameter Specification Sensor Type MQ137 Target Gas Ammonia (NH₃) Sensing Range 5 ppm – 500 ppm Operating Voltage 5V DC Output Type Analog (AO), Digital (DO) Preheat Time 24–48 hours recommended for stable performance Load Resistance (RL) Adjustable via potentiometer Response Time <10s Recovery Time <30s Operating Temperature -10°C to 50°C Relative Humidity <95% RH Module Dimensions Approx. 32mm × 20mm × 22mm Weight ~8g Working Principle The MQ137 sensor works on the semiconducting metal oxide (SnO₂) principle. The resistance of the sensitive material changes when it comes in contact with ammonia gas molecules. This change in resistance is converted into an electrical signal which can be read by microcontrollers like Arduino or ESP32. The higher the NH₃ concentration, the lower the resistance and hence the higher the output voltage. Applications of MQ137 NH3 Sensor Air quality monitoring systems Agricultural and livestock environments (for detecting NH₃) Industrial safety and gas leakage detection Environmental research and IoT-based air monitoring Smart HVAC systems Waste management monitoring systems Laboratory gas measurement setups How to Interface MQ137 NH3 Sensor with Arduino Connect VCC → 5V, GND → GND, AO → A0 pin on Arduino, and DO → Digital pin (optional). Allow the sensor to preheat for 24 hours for accurate readings. Read analog values using the analogRead() function. Convert raw analog data into NH₃ concentration (ppm) using calibration curves. ✅ For a detailed tutorial and example code, check out our YOUTUBE on MyTechLearner Calibration Before taking measurements, the MQ137 NH3 sensor requires calibration. It should be exposed to known concentrations of ammonia gas to generate a proper resistance (RS/R0) curve. Calibration ensures accurate results in your application. Package Includes 1 × MQ137 NH3 Gas Sensor Module Why Buy from Shektronix? At Shektronix, we ensure you receive authentic and quality-tested components. Every sensor is tested for performance and packaged safely for reliable delivery across India. We also provide technical documentation, tutorials, and sample Arduino codes for easy integration. External Resource (DoFollow Link) For the MQ137 datasheet and detailed technical documentation, visit the official Winsen MQ137 Datasheet. Internal Links Explore other Gas Sensors Buy Arduino Uno Compatible Board to interface with MQ137