Match the reference to the application.
The design specifies HTU21D temperature and humidity measurement. Keep the sensing opening, filter and environmental exposure in the assembly review.
Review the specification →GUILCOR · Digital sensing
HTU21D
humidity and temperature sensors
Digital relative humidity and temperature sensing for HVAC and embedded environmental monitoring. Match the sensor opening and filter option to the actual exposure.
Understand the reference
Choose protection without hiding the measurement.
The sensing polymer needs contact with the sampled air. A filter can help protect the opening, but does not make the complete probe suitable for every chemical, condensation or immersion condition.
SELECTION / YOUR APPLICATION
Is HTU21D the right starting point?
Review HDC1080 alongside HTU21D.
Compare the humidity and temperature channels, host interface, electrical requirements and installation. The enclosure and exposure of the sensing opening are part of the selection.
Explore HDC1080 →Keep the complete specification together.
Keep the exact device and host-driver references. Check commands, data conversion, connector and protective opening as well as the required measurement interval.
Prepare your enquiry →These links support a specification review. They do not establish interchangeable parts or availability of a complete assembly.
Interactive application guide
Review the filter and exposure choice.
This guide helps prepare a construction discussion. A filter option is not an enclosure ingress-protection rating.
Protection review
Required application check
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Technical reference
Reference details for the application.
| IC temperature range | −40 to +125 °C |
|---|---|
| Humidity range | 0 to 100 %RH |
| Supply | 1.5 to 3.6 V |
| Typical humidity accuracy | ±2 %RH from 20 to 80 %RH |
| Typical temperature accuracy | ±0.3 °C from +5 to +60 °C |
| Filter option | HTU21D without filter; HTU21DF with filter |
Apply the limits to the right component.
The sensing IC, finished probe and host electronics have separate requirements. Cable insulation, sealing, connector, supply and mounting may impose a narrower operating range. A temperature step is not an accuracy guarantee, and an electronic conversion time is not a thermal response time.
Useful in air-handling and environmental devices. Evaluate recovery after condensation and confirm the installation response with the chosen membrane.
Wiring and integration
Specify the electrical interface and sensing path.
Device connections
Check the exact part and measurement command. Keep soldering, cleaning, coating and adhesive processes compatible with the humidity-sensitive element.
Shared bus integration
SDA and SCL usually need pullups to a compatible logic supply. Select them for bus capacitance, rise time and the devices that pull the lines low. Cable length, connectors and level shifters change the electrical behaviour.
Use 7-bit addresses consistently in the host API. Check clock stretching, timeout and recovery support. Successful communication does not prove that the reading is fresh or that the sensor is mounted at a representative measurement point.
Acquisition sequence
Make each reading traceable.
Discover
Confirm the part, address, supply and measurement mode.
Convert
Issue the device-specific command and satisfy its timing and power needs.
Validate
Read the correct registers, check CRC where provided and reject invalid or stale results.
Use
Apply the correct decoder or compensation, units and application limits.
Measurement quality
Separate electrical behaviour from thermal performance.
Accuracy and calibration
Choose the error limit over the actual operating interval. Add installation and readout effects. Define any calibration and periodic verification required by the application; factory calibration does not establish a universal no-maintenance policy.
Response and mounting
A sheath, potting material and mounting contact change how fast the sensing element follows the medium. Verify response in the intended flow and installation, rather than using conversion time as the finished-probe response.
Power and self-heating
Average dissipation depends on supply, conversion duty and surrounding electronics. Test the assembled probe at the intended reading rate. Do not assume a universal self-heating offset from the interface name.
Form factor library
Choose your probe format.
Choose the shape and mounting for the measurement point. These are GUILCOR probe families and a design service; confirm the compatible element, dimensions, cable and complete assembly for the selected reference.
Frequently asked questions
Questions before specifying the assembly.
Does the filter make the sensor waterproof?
A sensor filter and a finished assembly rating are different. Confirm the complete housing, exposure and intended measurement path.
Can all I²C sensors share one bus?
Only when addresses, voltage levels, timing and host support are compatible. Fixed duplicate addresses may require a multiplexer or separate bus.
Is I²C a long-distance industrial interface?
It is commonly used for communication within electronic assemblies. Longer cables require an electrical design and validation appropriate to the installation; there is no universal permitted length.
What should I send for a probe quotation?
Send the reference and full ordering code, measured quantities, operating interval, error and response requirements, mounting drawing, cable and connector, host interface and quantity.
Technical sources
Continue with the reference documents.
GUILCOR / YOUR ENQUIRY
Define your HTU21D enquiry.
Describe both the electrical interface and the air reaching the sensor. Include the enclosure, airflow and exposure conditions when requesting an assembled probe.
Missing a reference or datasheet?
Send the component marking, equipment reference and any photographs or documents you have. These provide a starting point for identifying what must be confirmed.
The outline helps prepare your enquiry. Copying it does not send a request.
FOUR DETAILS THAT MOVE THE DISCUSSION FORWARD
01
Device and host
Exact device or module, interface, host or driver, supply and logic levels, addressing or wiring and measurement commands.
02
Measurement conditions
Temperature and humidity intervals, required accuracy and update rate, airflow, condensation risk, contamination and any additional measured quantities.
03
Assembly and connection
Sensing opening or filter, enclosure and ventilation, mounting location, nearby heat sources, connector and cable arrangement.
04
Project and validation
Sample and production quantities, target delivery, calibration or documentation needs, and the checks required before approval.