Winsen MH-Z19C
A compact NDIR CO₂ module with built-in temperature compensation and UART/PWM outputs for indoor air quality, ventilation and OEM integration.
Key Specifications
Product Positioning
Winsen positions the MH-Z19C as a small general-purpose CO₂ module for IAQ monitoring, ventilation and air-purification applications.
Official Resources
Technical data on this AirAlign page is based only on the manufacturer’s official product information. For integration, compliance and purchasing decisions, verify the latest manufacturer documentation.
View Winsen MH-Z19C Official PageAirAlign is an independent informational resource and is not affiliated with the manufacturer. Specifications can change; manufacturer documentation remains authoritative.
MH-Z19C — CO₂ PWM/UART power and time response
The MH-Z19C is a 5 V NDIR CO₂ module whose UART logic and PWM signals must be read using the manufacturer’s protocol and timing. Its cited 125 mA peak demand matters even if average draw is below 40 mA; weak power rails can produce invalid warm-up readings. For controlled ventilation, allow the specified preheat and up to 120 s T90 response when configuring fan control. The optional ppm measurement spans do not mean every ordered module automatically has the same firmware settings or factory baseline behavior.
Winsen MH-Z19C — 5 V NDIR CO₂ integration — engineering selection and model documentation
The published manufacturer values below are bounded to their orderable range, test conditions and actual interface, not general guarantees about every relative in the same sensor family.
| Parameter | Manufacturer evidence | Engineering boundary |
|---|---|---|
| Optical and gas principle | Gold-plated non-dispersive infrared (NDIR) chamber measures CO₂ with temperature compensation | Not oxygen, methane or a VOC-derived equivalent-CO₂ signal. |
| Order-dependent range | 400–2,000 / 5,000 / 10,000 ppm selectable versions | The controller must know actual calibrated factory range; output code alone does not prove 10k ppm accuracy. |
| Accuracy | ±(50 ppm + 5% of reading); reference at manufacturer conditions | At 1,000 ppm the combined nominal band is about ±100 ppm, not ±5% alone. |
| Electrical rail and startup | 5.0 ±0.1 V DC; <40 mA average, up to 125 mA measurement peaks; ~1-minute preheat | Dimension low-noise 5 V power supply and mark preheat measurements invalid. |
| Actual signals | 3.3 V TTL UART and PWM, not built-in RS485 or 24 V industrial current loop | Configure actual UART baud, PWM scaling, frame checks and high/low logic voltages. |
| Gas response and ambient | T90 <120 s; −10 to +50 °C; 0–95%RH noncondensing | A fast UART refresh cannot shorten the gas exchange step response. |
System integration and calibration
For greenhouses, mushroom farms and 24-hour occupied rooms, evaluate the MH-Z19C’s automatic baseline correction against the reality of never reaching outdoor CO₂ background; correct using a verified fresh-air or span reference rather than allowing self-calibration to create systematic error. Keep the optical gas entry unobstructed and away from heat, condensate, operator exhalation and stagnant enclosures. A similar MH-Z19D footprint does not guarantee identical firmware defaults or environmental rating. Site CO₂ control and personnel oxygen-deficiency alarms remain separate safety functions.
Source and exact-order documentation: Original manufacturer catalogue, page and/or technical data sheet. Any version- or test-bound claim must be checked against the supplied production label before procurement.
AirAlign model-specific technical editorial update · 25 October 2026. These OEM values are not independently calibrated, certified, or evidence of active supplier stock.