Winsen MH-Z14A Intelligent Infrared Carbon Dioxide Module User Manual

: June 17, 2024
: Winsen

Table of Contents

Winsen MH-Z14A Intelligent Infrared Carbon Dioxide Module
Product Information
Product Usage Instructions
Statement
Profile
Applications
Main functions and features
Main technical parameters
Structure
Automatic Baseline Correction
Important Notes
Contact Information
References
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Winsen MH-Z14A Intelligent Infrared Carbon Dioxide Module

Winsen-MH-Z14A-Intelligent-Infrared-Carbon-Dioxide-Module-
product

Product Information

Specifications:

Working voltage: 4.5 V ~ 5.5V DC
Average current: < 60 mA (@5V input)
Peak current: 150 mA (@5V input)
Interface level: 3.3 V (5V compatible)
Measuring range: 0~10000ppm (optional)
Output signal: Serial Port (UART, TTL level), PWM Analog output (DAC), 0.4-2V
Preheat time: 3min
Response Time: T90 < 120s
Working temperature: 0 ~ 50°C
Working humidity: 0 ~ 90%RH (no condensation)
Weight: 15 g
Lifespan: >5 years
Target Gas: Carbon Dioxide (CO2)

Applications:
The Intelligent Infrared Carbon Dioxide Module is suitable for various applications including:

HVAC refrigeration equipment
Air quality monitoring equipment
Fresh air system
Air purification equipment
Smart home
Schools

Main functions and features:

Gold-plated chamber, waterproof & anti-corrosion treatment
High sensitivity, low power consumption
Good stability
Temperature compensation, excellent linear output
Output modes: UART, analog voltage signal, PWM wave
Long lifespan
Anti-water vapor interference
No poisoning

Structure:
The Intelligent Infrared Carbon Dioxide Module consists of the following pins:

Pin 1: Vin – Voltage Input
Pin 2: GND – Analog Output (0.42V)
Pin 3: PWM – HD (Zero calibration, low level for more than 7 seconds valid)
Pin 4: NC
Pin 5: UARTRXD – TTL Level input
Pin 6: UARTTXD – TTL Level Output

Product Usage Instructions

Mounting and Installation:
Follow the steps below to mount and install the Intelligent Infrared Carbon Dioxide Module:

Select a suitable location for installation.
Avoid applying pressure to the gilded plastic chamber during welding, installation, and use.
If placed in a small space, ensure proper ventilation, especially for diffusion.

Connection:
To connect the module to your system, follow the steps below:

Connect the Vin pin to the voltage input of your system.
Connect the GND pin to the ground of your system.
Connect the PWM pin to the HD (Zero calibration) pin of your system.
Connect the UARTRXD pin to the TTL level input of your system.
Connect the UARTTXD pin to the TTL level output of your system.

ABC Function (Automatic Baseline Correction):
The ABC function allows the sensor to perform zero-point judgment and automatic calibration after a continuous operation period. Follow the steps below to use the ABC function:

Ensure the sensor is placed in clean air for over 1 hour for better performance.
The automatic calibration cycle is every 24 hours after powering on.
The default setting from July 2015 includes a built-in automatic calibration function.
If using the sensor in environments such as greenhouses, farms, or refrigerators, where automatic calibration is not suitable, disable the ABC function.
In such cases, perform zero detection regularly and perform zero calibration by command or manually.

Frequently Asked Questions:

Q: What is the lifespan of the MH-Z14A NDIR CO2 Module?
A: The module has a lifespan of over 5 years.
Q: What is the measuring range of the module?
A: The module has an optional measuring range from 0 to 10000ppm. Please refer to Table 2 for more details.
Q: How often does the ABC function perform automatic calibration?
A: The ABC function performs automatic calibration every 24 hours after powering on.
Q: Can the module be used in greenhouses or farms?
A: The ABC function is not suitable for greenhouses, farms, or refrigerators. In such cases, it is recommended to disable the automatic calibration function and perform zero detection and calibration regularly.

Statement

The copyright of this manual belongs to Zhengzhou Winsen Electronics Technology Co., LTD. Without written permission, any part of this manual shall not be copied, translated, or stored in a database or retrieval system, and also can’t spread through electronic, copying, or record ways. Thanks for purchasing our product. To enable customers to better use the product and reduce the faults caused by misuse, please read the manual carefully and operate it correctly according to the instructions. If users disobey the terms or remove, disassemble, or change the components inside of the sensor, we shall not be responsible for the loss. The specifics such as colour, appearance, sizes …etc., please in kind prevail.

We are devoting ourselves to product development and technical innovation, so we reserve the right to improve the products without notice. Please confirm it is the valid version before using this manual. At the same time, users’ comments on the optimized way are welcome. Please keep the manual properly, to get help if you have questions during the usage in the future.

Profile

MH-Z14A NDIR Infrared gas module is a common type, small-size sensor, using the non-dispersive infrared (NDIR) principle to detect the existence of CO2 in the air, with good selectivity, non-oxygen dependent and long life. Built-in temperature compensation; and it has digital output, analog voltage output, and PWM output. This common infrared gas sensor is developed by the tight integration of mature infrared absorbing gas detection technology, precision optical circuit design and superior circuit design.

Applications

HVAC refrigeration equipment, air quality monitoring equipment, fresh air systems, air purification equipment, smart homes, and schools.

Main functions and features

Gold-plated chamber, waterproof & anti-corrosion treatment
High sensitivity, Low power consumption
Good stability
Temperature compensation, excellent linear output
Output modes: UART, analog voltage signal, PWM wave
Long lifespan
Anti-water vapor interference
No poisoning

Main technical parameters

Working voltage	4.5 V ~ 5.5V DC
Average current	< 60 mA(@5V input)
Peak current	150 mA(@5V input)
Interface level	3.3 V (5V compatible)
Measuring range	0~10000ppm optional (refer to table 2)

Output signal

| Serial Port (UART, TTL level)
PWM
Analog output( DAC), 0.4-2V
Preheat time| 3min
Response Time| T90 < 120s
Working temperature| 0℃ ~ 50℃
Working humidity| 0~90%RH (no condensation)
Weight| 15 g
Lifespan| >5 year
Target Gas| Measuring Range| Accuracy
---|---|---

Carbon Dioxide (CO2)

| 0~2000ppm| ±(50ppm

+3%reading value)

0~5000ppm

0~10000ppm

| ±10% reading

value

Structure

$Winsen-MH-Z14A-Intelligent-Infrared-Carbon-Dioxide-Module-fig- $2$$ $Winsen-MH-Z14A- Intelligent-Infrared-Carbon-Dioxide-Module-fig- $3$$

PIN

|

Description

---|---
Pad1/Pad15/Pad17/Pad23| Vin Voltage Input
Pad2/Pad3/Pad12/Pad16/Pad22| GND
Pad4/Pad21| Analog Output (0.4～2V)
Pad6/Pad26| PWM
Pad8/Pad20| HD (Zero calibration, low level for more than 7 seconds valid)
Pad7/Pad9| NC
Pad11/Pad14/Pad18/Pad24| UART（RXD） TTL Level input
Pad10/Pad13/Pad19/Pad25| UART（TXD） TTL Level Output

Automatic Baseline Correction

Automatic Baseline Correction (ABC function)
ABC function refers to the sensor itself doing zero point judgment and automatic calibration procedure intelligently after a continuous operation period. The automatic calibration cycle is every 24 hours after powered on. The zero point of automatic calibration is 400ppm. From July 2015, the default setting has been with a built-in automatic calibration function. To use the sensor better, the sensor must be placed in clean air for over 1 hour.

ABC function is suitable for office and home environments etc…., but not for greenhouses, farms, refrigerators etc…., in which it requires shutting down the automatic calibration function. Then the user should do zero detection regularly, and zero calibration by command or manually.

Important Notes

Please avoid the pressure of its gilded plastic chamber from any direction, during welding, installation, and use.
When placed in a small space, the space should be well-ventilated, especially for diffusion windows.
The sensor should be away from heat, and avoid direct sunlight or other heat radiation.
Do not use the sensor in a highly dusty environment for a long time.
To ensure normal work, the power supply must be in the 4.5V~5.5V DC range, the power current must be not less than 150mA. Out of this range, it will fail the sensor. (The concentration output is low, or the sensor can not work normally.)
During the zero point calibration procedure manually, the sensor must work in a stable gas environment (400ppm) for over 20 minutes. Connect the HD pin to a low level (0V) for over 7 seconds.