Target: Temperature and Relative Humidity
Model: ZS21
Detection principle: Semiconductor, Module
Characteristics: Fully calibrated, Wide power supply voltage range, from 2.0V to 5.5V,Digital output, standard I²C signal

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ZS21 is a brand new product equipped with a dedicated ASIC sensor chip, a high-performance semiconductor silicon-based capacitive humidity sensor and a standard on-chip temperature sensor, and is connected with a high-performance 8-bit microcontroller to output standard I2C data signals. At the same time, each sensor is calibrated in a high-precision temperature and humidity verification box, so the product has good consistency; ZS21 products use special humidity-sensitive materials, so that their performance is extremely stable in high-temperature and high-humidity environments. It has the advantages of fast response, strong anti-interference ability, and high cost performance.


  • Home appliance fields: home appliance, humidity control, HVAC, dehumidifiers, smart thermostats, and room monitors;
  • Commercial fields: smart buildings, office, airport, supermarket, shopping mall;
  • Industrial fields: automobiles, testing equipment, and automatic control devices;
  • Other fields: data loggers, weather stations, medical and other related temperature and humidity detection devices.


  • Fully calibrated
  • Wide power supply voltage range, from 2.0V to 5.5V
  • Digital output, standard I²C signal
  • Quick response and strong anti-interference ability
  • Excellent long-term stability under high humidity condition
  • Low power consumption and high precision


Parameter Condition Min Typical Max Unit
Resolution Typical - 0.024 - %RH
Accuracy error1 Typical - ±3 - %RH
Repeatable - - ±0.1 - %RH
Hysteresis - - ±1.0 - %RH
Non-linear - - <0.1 - %RH
Response time2 τ63 % - <8 - s
Scope of work3 - 0 - 100 %RH
Prolonged Drift4 Normal - < 1 - %RH/yr

* The description and specifications might be changed without notice. Please contact us for the latest information before placing orders.

Technical Support:

Customized technical design and function, LOGO and package are available without extra charge (including molding fee) for mass volume.

The sensors don't have sleeping mode. It can be set in program if needed.

All Winsen products go through strict inspections and tests to make sure they are 100% qualified before shipping out.

The sensor has been fully tested (not calibrated) before leaving the factory. However, after transportation and storage, the environment conditions change, and the surface of the sensor absorbs moisture, mixed gas, pollution matters, etc. It is recommended that customers perform aging and calibration after sensors become stable according to the program and use occasions of the whole device.

15﹪-90﹪RH without condensation,greater or less than this range or long-term high temperature and high humidity will affect the life of the sensor.

Our sensors are certified with CE, 3C, ROHS, anti-explosion, fire prevention, and coal mining safety according to different applications. And we provide assistance for new certification.

Many factors can cause the sensor to fail such as broken wires in transportation, poisoning, falling off of the sensitive material, damage to the heating wire (device), etc. Please find specific cause in each category with Winsen’s aftersales.

Winsen provides professional consultation and service before and after sales. We will recommend the best fitting sensor for your demand. If you have any problem, don’t hesitate to email us to

Due to high volume of daily incoming emails and time zone difference, we may not be able to reply your emails immediately. But we will reply to your inquiry in 24 business hours.