---
product_id: 453127517
title: "1PCS MQ-138 MQ138 Formaldehyde HCHO Volatile Organic Compounds (VOC) Gas Sensor Module with Alarm Signal Light"
brand: "huaban"
price: "$220"
currency: NZD
in_stock: true
reviews_count: 5
category: "Huaban"
url: https://www.desertcart.nz/products/453127517-1pcs-mq-138-mq138-formaldehyde-hcho-volatile-organic-compounds-voc
store_origin: NZ
region: New Zealand
---

# 5V heating voltage for rapid sensor activation <1s response time for instant air quality alerts -10~50°C operating range for versatile environments 1PCS MQ-138 MQ138 Formaldehyde HCHO Volatile Organic Compounds (VOC) Gas Sensor Module with Alarm Signal Light

**Brand:** huaban
**Price:** $220
**Availability:** ✅ In Stock

## Summary

> 🌬️ Breathe Smart, Live Safer — The Future of Air Quality is Now!

## Quick Answers

- **What is this?** 1PCS MQ-138 MQ138 Formaldehyde HCHO Volatile Organic Compounds (VOC) Gas Sensor Module with Alarm Signal Light by huaban
- **How much does it cost?** $220 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.nz](https://www.desertcart.nz/products/453127517-1pcs-mq-138-mq138-formaldehyde-hcho-volatile-organic-compounds-voc)

## Best For

- huaban enthusiasts

## Why This Product

- Trusted huaban brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Rapid Detection, Zero Delay:** Experience near-instant formaldehyde sensing with a lightning-fast <1 second response time, keeping your environment safe without missing a beat.
- • **Energy-Efficient Smart Sensing:** Consumes less than 0.9W power, making it ideal for continuous monitoring without draining your system’s resources.
- • **Visual Alarm for Instant Awareness:** Integrated alarm signal light provides immediate visual alerts, so you’re always in the know and can act fast to protect your space.
- • **Built to Endure, Designed to Perform:** Reliable operation across a wide humidity range (up to 95% RH) and temperatures from -10°C to 50°C ensures consistent performance wherever you need it.
- • **Precision Sensitivity in Compact Form:** Detect VOCs from 1 to 100ppm with >3% sensitivity, all packed into a sleek 35x40x28mm module that fits effortlessly into your smart home or industrial setup.

## Overview

The MQ-138 Formaldehyde HCHO VOC Gas Sensor Module is a compact, energy-efficient device engineered for rapid and precise detection of harmful formaldehyde concentrations ranging from 1 to 100ppm. Operating reliably across diverse environmental conditions (-10 to 50°C, up to 95% humidity), it features a lightning-fast response time under 1 second and an integrated visual alarm for immediate hazard notification. Ideal for smart home integration and industrial air quality monitoring, this sensor ensures you never compromise on safety or performance.

## Description

Features: 1, Heating voltage: 5 ±0.2V (AC·DC) 2, Working current: 180mA 3, Circuit voltage: DC5V (Max DC 24V) 4, Load resistance: 10K (adjustable) 5, Test concentration range :1-100ppm 6, Clean air voltage:  3% 8, Response time: <1S (3-5 minute warm-up, theory preheating time 48 hours) 9, Response time: <30S 10, Component power consumption: <0.9W 11, Working temperature: -10 ~ 50 oC (nominal temperature 20 oC) 12, Humidity: 95% RH (nominal humidity 65% RH) 13, Life: 5 years 14, Size: 35mm×40mm×28mm 15, Weight Size: 15g (approximately)

Review: As described, there are 9 unique sensors in this kit. You can tell which is which by looking at the metal casing of the sensor where they silk screen the "MQ- " part number.
Review: Worked great for a DIY breathalyzer on a MSP430, was able to get relatively accurate results compared to a certified police breathalyzer. Follow the burn in procedure, it's in the data sheet.

## Features

- MQ-138 Formaldehyde HCHO Gas Sensor Module
- Heating voltage: 5 +0.2V (AC·DC);Working current: 180mA;Circuit voltage: DC5V (Max DC24V);Clean air voltage: < 1.5V
- Test concentration range :1-100ppm ; Sensitivity: >3% ; Response time: < 1S (3-5 minute warm-up, theory preheating time 48 hours)
- Working temperature: -10 ~ 50 oC (nominal temperature 20 oC) ; Humidity: 95% RH (nominal humidity 65% RH)
- Size: 35mm×40mm×28mm

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B082386TW7 |
| Alarm | Visual |
| Are batteries included? | No |
| Best Sellers Rank | #126,747 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #291 in Indoor Air Quality Meters |
| Brand | HUABAN |
| Customer Reviews | 4.1 4.1 out of 5 stars (60) |
| Date First Available | 18 September 2020 |
| Item Weight | 20 g |
| Item model number | MQ-136 |
| Manufacturer | HUABAN |
| Model number | MQ-136 |
| Net Quantity | 1 Count |
| Operating Humidity | 95 percent |
| Product Dimensions | 35D x 28W x 40H Millimeters |
| Sensor Type | gas sensor |
| Style | Compact |

## Product Details

- **Alarm:** Visual
- **Brand:** HUABAN
- **Item Weight:** 0.02 Kilograms
- **Manufacturer:** HUABAN
- **Operating Humidity:** 95 percent
- **Product Dimensions:** 35D x 28W x 40H Millimeters
- **Sensor Type:** gas sensor
- **Style:** Compact

## Images

![1PCS MQ-138 MQ138 Formaldehyde HCHO Volatile Organic Compounds (VOC) Gas Sensor Module with Alarm Signal Light - Image 1](https://m.media-amazon.com/images/I/71EhBJRrx0L.jpg)
![1PCS MQ-138 MQ138 Formaldehyde HCHO Volatile Organic Compounds (VOC) Gas Sensor Module with Alarm Signal Light - Image 2](https://m.media-amazon.com/images/I/71zSE+OPJfL.jpg)

## Available Options

This product comes in different **Size** options.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Review
*by F***C on 16 May 2025*

As described, there are 9 unique sensors in this kit. You can tell which is which by looking at the metal casing of the sensor where they silk screen the "MQ- " part number.

### ⭐⭐⭐⭐⭐ Review
*by A***K on 20 August 2025*

Worked great for a DIY breathalyzer on a MSP430, was able to get relatively accurate results compared to a certified police breathalyzer. Follow the burn in procedure, it's in the data sheet.

### ⭐⭐⭐⭐ Review
*by M***S on 1 May 2024*

bought this for a science fair project. It worked great at sensing ammonia but did not exhibit a response to hydrogen sulfide. It was easy to integrate with an Arduino Uno board and I used it to trigger an alarm circuit. Good buy even though the target analyte was mis-advertised.

## Frequently Bought Together

- HUABAN 1PCS MQ-138 MQ138 Formaldehyde HCHO Volatile Organic Compounds (VOC) Gas Sensor Module with Alarm Signal Light
- EC Buying MS1100 Gas Sensor, VOCs Sensor for Air Quality, Carbon Dioxide Formaldehyde Monitoring TVOC CO2 Gas Sensor Module, Sensor Arduino I2C

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*Product available on Desertcart New Zealand*
*Store origin: NZ*
*Last updated: 2026-02-17*